lördag 19 juni 2010

A window into the phenomen of Life?

Hurricanes are characterized by heavy winds spiralling around the eye of the storm. They can be very stable and travel thousands of miles while changing in shape, velocity, rotation speed and strength. Inside the 'wheel' are strong forces born, like infrasounds, magnetic changes and levitation, gravity...

Skyrmions was rediscovered in 1983 in the context of Quantum Chromodynamics (QCD). A skyrmion contains 'knots' in its magnetization; the vector character of the magnetization leads to more complex topological states. The term skyrmion derives from the analogy with the Skyrme model for nucleons in pion (electron, muon, tau) field theory, and is used in the modelling of atomic nuclei as quantized skyrmions. Skyrmions are topological soliton solutions whose conserved topological charge B is identified with the baryon number of a nucleus. Apart from an energy and length scale, the Skyrme model has just one dimensionless parameter m proportional to the pion mass. It has been found that a good fit to experimental nuclear data requires m to be of order 1 (reals?). Modelling of atomic nuclei here.

Roaming through a skyrmion. When an electron moves through a special type of magnetic texture called a skyrmion, its magnetic moment (spin) twists to adjust to the skyrmion's local spin structure (ribbon-like pattern). This twisting changes the electron's direction of travel and pushes the electron and the skyrmion in opposite directions (not shown). From Nature (1).

It is interesting to observe skyrmions in the more conventional, 3-D magnetic system MnSi at higher temperatures. Chlorophyll resembles much MnSi basic unit. Chlorophyll support assembly and accumulation of light-harvesting complexes, only its central atom is Mg and its 'arms' are C. Modifications that introduce electronegative groups on the periphery of the chlorophyll molecule withdraw electrons from the pyrrole nitrogens and thus reduce their basicity. Consequently, the tendency of the central Mg to form coordination bonds with electron pairs in exogenous ligands, a reflection of its Lewis acid properties, is increased, here.

The Dirac world.
There are a force emerging perpendicular to this electron movement, and also consequently a repelling force (antimatter?). This will create a cone of different magnetism (and gravity?) expending forth and back. A non-material Dirac cone creating topology and hierarchy and matter condensation? Gravity emergense in the 4-D? Dirac electrons can only exist on the honeycomb lattice. About the Carbon world:

Graphene's band dispersion and low energy Dirac cone. From EV Castro.

Castros research group:
Graphene is a semi-metal, with a linearly vanishing density of states (DOS) at zero energy (the Fermi level for the undoped material). Near the Fermi energy, the DOS fills up to a constant plateau (also predicted in a CPA) but in addition has a sharp peak closer to zero energy, reminiscent of the delta function of the quasi-localized state for a single impurity. A study of the inverse participation ratio showed that the states contributing to this feature have a real space decay similar to the single impurity state (~1/r, where r is the distance to the vacancy). This work in currently being extended to study long range (Coulomb) impurity potentials.

We also developed a tight-binding study of the graphene bilayer, subject to a perpendicular electric field. This turns out to be a very interesting system for applications, since the bilayer opens a gap, tunable via the external electric field, and managed to obtain a consistent description of the measured cyclotron mass and energy gap as a function of the external field.

We showed that a relative rotation of the layers (a rather common stacking defect in graphite, often observed in STM studies of its surface) has profound effects on the electronic structure near the Fermi level:
* the low energy dispersion remains linear, as in a single layer
* the Fermi velocity can be significantly reduced with respect to the single layer value
* a perpendicular electric field does not open a gap.
Gap opening in a biased graphene bilayer. An energy gap is created if the material is placed between positive and negative electrodes. The gap arises because the transverse voltage causes an excess of negatively charged electrons in one layer and an excess of positively charged “holes” in the other layer. These electrons and holes are believed to pair up to create quasiparticles, which behave differently than their constituent particles.

A magnetic field was also applied to the bilayer, which caused the quasiparticles to move in circular orbits – an effect called cyclotron resonance. The team measured the period of this resonance, which depends on the mass of the quasiparticles. The team discovered that this cyclotron mass increased as the applied voltage increased from zero to about 100 V, allowing them to conclude that the energy gap was also changing from zero to about 150 meV (2).

A peculiar feature of electrons and holes in graphene is that they move through the material as if they have no rest mass – something that makes the material a very good conductor. However, the quasiparticles have a rest mass and according to Castro Neto, this mass leads to an energy gap that must be overcome before current can flow.
What say Castro Neto? He looks at quantum phase transitions and graphene.
Many phases of matter are characterized by order of some electronic degree of freedom such as spin (as in the case of spin density waves - SDW), or charge (as in the case of charge density waves - CDW). Other phases are characterized by more complicated order parameters that are directly related to many-body effects (as in the casea of superconductivity). It is possible to tune between phases with order and without order by tunning some parameter such as the temperature of the system. These finite temperature phase transititons have been well studied in the context of classical critical phenomena. Much less is known by phase transitions that occur at zero temperature in which quantum fluctuations play an important role. These quantum phase transitions (QPT) are responsible for very unusual behavior that cannot be described within traditional theoretical frameworks. QPT transitions can be tuned by the application of pressure, magnetic field, or even chemical modification, that unavoidably introduces disorder in the material. Disorder can strongly affect QPT because quantum fluctuations are very sensitive to geometrical constraints. Cold atom systems, high temperature superconductors, transition metal dichalcogenides, and heavy fermion materials are example of systems where QPT are believed to play an important role.

Example of a Quantum Phase Transition: T is temperature and Fm is a tunning parameter.

Spin and charge densities as opposed to many-body systems, which only them can have superconductions and superpositions. Of course, it takes two to tangos. The Scrödinger cat phenomen...

This is said to be usable for molecular sensors. Surprise? I think at once of sensors in biology. Carbon is central in biology, as also cyclotrone resonances (Liboff, TGD).

Is this 'gap opening' the same as the A-phase? Could this be the quantum window in biology, giving rise to paranormal experiences? And also diseases like MS, arthritis, pain...? The meridian functionings? The beginning of the entangled qubit-thing, used by Rakovic. Some kind of makrostate qubit? A chrystalline living oscillating phase that can be managed by small changes in temp.,pressure, pH? This list sound familiar from the nerve pulse. But how learn to dance?.

Chrystals of different kinds. The A-phase.
The abstract to another Nature article 17.6 (3).
Crystal order is not restricted to the periodic atomic array, but can also be found in electronic systems such as the Wigner crystal or in the form of orbital order, stripe order and magnetic order. In the case of magnetic order, spins align parallel to each other in ferromagnets and antiparallel in antiferromagnets (= diamagnetic and paramagnetic order?) In other, less conventional, cases, spins can sometimes form highly nontrivial structures called spin textures. Among them is the unusual, topologically stable skyrmion spin texture, in which the spins point in all the directions wrapping a sphere, the skyrmion. The skyrmion configuration in a magnetic solid is anticipated to produce unconventional spin–electronic phenomena such as the topological Hall effect. The crystallization of skyrmions as driven by thermal fluctuations has recently been confirmed in a narrow region of the temperature/magnetic field (T–B) phase diagram in neutron scattering studies of the three-dimensional helical magnets MnSi and Fe1−xCoxSi. With a magnetic field of 50–70 mT applied normal to the film, we observe skyrmions in the form of a hexagonal arrangement of swirling spin textures, with a lattice spacing of 90 nm. The related T–B phase diagram is found to be in good agreement with Monte Carlo simulations. In this two-dimensional case, the skyrmion crystal seems very stable and appears over a wide range of the phase diagram, including near zero temperature. Such a controlled nanometre-scale spin topology in a thin film may be useful in observing unconventional magneto-transport effects.

a, b, Helical (a) and skyrmion (b) structures predicted by Monte Carlo simulation. c, Schematic of the spin configuration in a skyrmion. d–f, The experimentally observed real-space images of the spin texture, represented by the lateral magnetization distribution as obtained by TIE analysis of the Lorentz TEM data: helical structure at zero magnetic field (d), the skyrmion crystal (SkX) structure for a weak magnetic field (50 mT) applied normal to the thin plate (e) and a magnified view of e (f). The colour map and white arrows represent the magnetization direction at each point.

a–c, Spin textures observed using Lorentz TEM obtained by Monte Carlo simulation. e–g, Spin textures after TEM. H, helical structure; SkX, skyrmion crystal structure; FM, ferromagnetic structure. d, h, Observed (d) and calculated (h) phase diagrams in the B–T plane. The colour bars in the phase diagrams indicate the skyrmion density per 10−12 m2 (d) and per d2 (h), d being the helical spin wavelength. Dashed lines show the phase boundaries between the SkX, H and FM phases. Stars in d and h indicate (T, B) conditions for the images shown in a–c and e–g, respectively.

Molecular orbital theory (4):
A molecular orbital is the volume within which a high percentage of the negative charge generated by the electron is found. The molecular orbital volume encompasses the whole molecule. The electrons would fill the molecular orbitals of molecules like electrons fill atomic orbitals in atoms.
- The molecular orbitals are filled in a way that yields the lowest potential energy for the molecule.
- The maximum number of electrons in each molecular orbital is two (Pauli exclusion principle.)
- Orbitals of equal energy are half filled with parallel spin before they begin to pair up (Hund's Rule.)
- Molecular orbitals are formed from the overlap (superpositions?) of atomic orbitals.
- Only atomic orbitals of about the same energy interact to a significant degree.
- When two atomic orbitals overlap, they interact in two extreme ways to form two molecular orbitals, a bonding molecular orbital and an antibonding molecular orbital.

Light waves can interact in-phase, which leads to an increase in the intensity of the light (brighter) and out-of-phase, which leads to a decrease in the intensity of the light (less bright). Electron waves can also interact in-phase and out-of-phase. In-phase interaction leads to an increase in the intensity of the negative charge. Out-of-phase interaction leads to a decrease in the intensity of the negative charge.

In-phase leads to wave enhancement similar to the enhancement of two in-phase light waves. Where the atomic orbitals overlap, the in-phase interaction leads to an increase in the intensity of the negative charge in the region where they overlap. This creates an increase in negative charge between the nuclei and an increase in the plus-minus attraction between the electron charge and the nuclei for the atoms in the bond. The greater attraction leads to lower potential energy.
Because electrons in the molecular orbital are lower potential energy than in separate atomic orbitals, energy would be required to shift the electrons back into the 1s orbitals of separate atoms. This keeps the atoms together in the molecule, so we call this orbital a bonding molecular orbital. The molecular orbital formed is symmetrical about the axis of the bond. Symmetrical molecular orbitals are called sigma, σ, molecular orbitals.

The second way that two atomic orbitals interact is out-of-phase. Where the atomic orbitals overlap, the out-of-phase interaction leads to a decrease in the intensity of the negative charge. This creates a decrease in negative charge between the nuclei and a decrease in the plus-minus attraction between the electron charge and the nuclei for the atoms in the bond. The lesser attraction leads to higher potential energy. The electrons are more stable in the 1s atomic orbitals of separate atoms, so electrons in this type of molecular orbital destabilize the bond between atoms. We call molecular orbitals of this type antibonding molecular orbitals. The molecular orbital formed is symmetrical about the axis of the bond, so it is a sigma molecular orbital with a symbol of σ*1s.
This is an simple box, like a Feynman diagram.
When two larger atoms atoms combine to form a diatomic molecule (like O2, F2, or Ne2), more atomic orbitals interact. The LCAO approximation assumes that only the atomic orbitals of about the same energy interact. For O2, F2, or Ne2, the orbital energies are different enough so only orbitals of the same energy interact to a significant degree.

The two 2py atomic orbitals overlap in parallel and form two pi molecular orbitals. Pi molecular orbitals are asymmetrical about the axis of the bond.

bond order = 1/2 (#e- in bonding MO's - #e- in antibonding MO's)

Oxygen, the negentropic element.
The molecular orbital diagram for a diatomic oxygen molecule, O2.

- O2 has a bond order of 2. Bond Order = 1/2(10 - 6) = 2
- The bond order of two suggests that the oxygen molecule is stable.
- The two unpaired electrons show that O2 is paramagnetic.
The bond between the carbon and oxygen in carbon monoxide is very strong despite what looks like a strange and perhaps unstable Lewis Structure. The plus formal charge on the more electronegative oxygen and the minus formal charge on the less electronegative carbon would suggest instability. The molecular orbital diagram predicts CO to be very stable with a bond order of three. About the geometry of molecular orbits here.

Other odd features.
Coexistence of both magnetic order and cooperative paramagnetic spin liquid behavior is possible, seen in spin glass phenomens, as instance. The temperature Tc is joined to a point in the phase diagram where a transition between two paramagnetic solutions happens. This gives liquid crystal properties, called a mesophase? "The existence of a long range intermolecular exchange interaction at all the temperatures is established by the collapse of the hyperfine structure in the spectra of the condensed samples. The comparison of the principal effective g- values in the solid phase with those of the isolated molecule obtained from the toluene solution spectra indicates that in the solid, the molecules pack keeping their molecular axes parallel. The drastic changes observed in the spectra when the sample reaches the smectic phase are interpreted as a consequence of the structure of this mesophase".
Long-range polarization in an antiferrimagnetic order has also shown a window of ferromagnetic order. An emergence of 2-D? An temp. dependent interference between the electric and magnetic properties? It is shown that there exists a transition between a Néel state and a quantum paramagnetic phase, characterized by broken translational invariance. The non-magnetic phase preserves the lattice rotational symmetry, and has a correlated plaquette nature.
A mirror symmetry is identified to characterize both electron and impurity magnetizations (spin polarizations) when the impurities are symmetrically (with respect to this mirror) positioned and when pinning fields are absent.

Fluorescence polarization and electron paramagnetic resonanse spectroscopy are used to study order and orientation of protein elements in biology.

Life is these multiphases? As Rakovic said, Life is not trying to eliminate the noise, but to use it to create oscillations and a new order. That is exactly some kind of superpositions of different em-properties (liquid chrystals?).

In oxides the O is shown to be important for the topology. It brings in the 'islands'. Here.
...homolog but also that grain boundaries are the preferential sites for oxide nucleation and the oxide islands formed along the grain boundaries show a faster growth rate than that on flat Cu surface. The oxidation on the faceted Cu(110) surface results in heterogeneous nucleation of oxide islands in the facet valleys and one-dimensional growth along the intersection direction of the facets. Self-organised nanostructures, obtained by oxidation of III–VI compounds It was established that self oxide surfaces possess numerous geometrical morphologies of nanostructures (wires, trees, self assembled networks).

The spin states are analogs to solitons? The charged excitations are very light, and form a degenerate Bose gas even at high temperatures. -> Oxide superconductors.
Complex oxide materials exhibit a tremendous diversity of behavior encompassing a broad range of functional properties, such as magnetism, ferroelectricity, and superconductivity. As diverse as this behavior is, an even richer spectrum of possibilities becomes available if one starts to combine different complex oxides together with atomic-scale precision to create new artificially structured, heterogeneous systems.

Quantum spin Hall effect in a transition metal oxide Na2IrO3 an antiferromagnetic order first develops at the edge, and later inside the bulk at low temperatures. The nontrivial topology is more ubiquitous in solids than expected.
A recent breakthrough in this field is the theoretical and experimental discoveries of the quantum spin Hall (QSH) effect in time-reversal symmetric insulators. Intuitively it can be regarded as two copies of QH systems with up and down spins, but is driven by the spin-orbit interaction (SOI) instead of the external magnetic field. The topological insulator is closely related to a Kramers doublet protected by the time-reversal symmetry, and corresponds to the presence or absence of gapless helical edge modes in the semi-infinite system.

The theoretical design of a topological insulator using HgTe/CdTe quantum wells, and it is shown that the lowtemp superconduction relies on large SOI and the fine tuning of the band structure. Therefore one important development is to realize more robust topological insulators at higher temperature by the larger SOI. Try to design topological insulators in 5d transition metal oxides by using the complex transfer integrals and the lattice geometry, which was shown.

Another interesting development is to study the interplay between the non-trivial topology and the electron correlation. Generally the electron correlation is stronger in d- and f-electrons than in s- and p-electrons. When we look at transition metal ions in the periodic table, the electron correlation is the strongest in 3d elements and decreases to 4d and to 5d elements because d-orbitals are more and more extended, while the SOI increases as the atomic number.

5d-orbitals are rather extended and subject to the large crystalline field. Under the octahedral crystalline field, d-orbitals are split into e(g) (x2 − y2, 3z2 − r2)- and t(2g) (xy, yz, zx)-orbitals by 10Dq of the order of 3eV. The SOI is quenched in e(g)-orbitals but remains effective in t(2g)-orbitals, which form effectively the triplet with ℓ(eff) = 1. Including the SOI, we obtain the states with the total angular momentum j(eff) = 3/2 and 1/2. The central idea is that the transfer integrals between these complex orbitals and oxygen orbitals become complex. This complex transfer integral is responsible for topological states in iridates ( - look also at the molecular orbital model).

Na2IrO3 whose layered crystal structure contains the honeycomb lattice, with each Ir atom surrounded by an octahedron of six O atoms, which leads to the similar energy level scheme as Sr2IrO4, i.e. one electron in j(eff) = 1/2-states, we can construct the effective single-band model on the honeycomb lattice. Since the O p-level ǫp are around 3eV lower than the Ir d-level ǫd we can integrate out p-orbitals to obtain the following effective Hamiltonian where [ij] and [[ij]] denote the nearest-neighbor (NN) and next-nearest-neighbor (NNN) pairs, respectively. The transfer integral t between a NN pair is real and spin-independent. The transfer integral between a NNN pair depends on spin, leading to a topological insulator, perpendicular to the honeycomb plane. With this convention, the transfer integral is a 2 × 2 matrix in the spin space. The key to these complex transfer integrals is the asymmetry between two paths connecting a NNN pair. The real transfer integral t′0 can be produced by the direct dd hopping and breaks the particle-hole symmetry.

To summarize these results, the transfer integrals are real and spin-independent for a NN pair, while complex and spin-dependent for a NNN pair, where ψ(~r) is the eight-component spinor field operator, and kX and kY are measured from K or K′ points. η’s, τ’s, and σ’s are the Pauli matrices for the valley (K or K′), sublattice (1 or 2), and spin (+ or −) degrees of freedom, respectively. Diagonally is a zig-zag geometry. The crossing point is at k = π for the zig-zag geometry, while at k = 0 for the armchair geometry, where k is the wavenumber along the edge. Anyway such crossing is protected by the Kramers theorem, and can get gapped only if the time-reversal symmetry is broken.

The circular movement in the skyrmions give rise to an helix. Carbon is an asymmetric molecule giving chirality.

Carbon is also one possible way Dirac electrons will enter. And Carbon will form a superposition upon the hexameric lattice as a trimeric sublattice. Oxygenal secondary lattice is hexagonal. I think this is very important in biology.

The intensity pattern in the A-phase is characterized by a six-fold symmetry. These patterns are exclusively seen in the plane perpendicular to the magnetic field. The A-Phase can be identfii ed as a hexagonal lattice of skyrmion tubes. The spin structure in the A-phase of MnSi is a so-called triple-Q state, i.e., a superposition of three helices under 120 degrees, and similar to the vortex lattice in superconductors.

Twenty years ago it has been predicted that skyrmions exist in anisotropic spin systems with chiral spin-orbit interactions, where they are expected to form crystalline structures. The origin of the topological Hall effect is a Berry phase collected by the conduction electrons when following adiabatically the spin polarization of topologically stable knots in the spin structure. Thus the Berry phase reflects the chirality and winding number of the knots. The topological Hall effect arises besides the normal Hall effect, which is proportional to the applied magnetic field, and the anomalous Hall effect that scales with ferromagnetic components of the magnetization.

This provides clear experimental evidence that the magnetic structure observed in neutron scattering has indeed the topological properties (chirality and winding number). The helimagnetic state may be understood as the result of a hierarchy of energy scales where ferromagnetic exchange is on the strongest scale and the isotropic spin-orbit interactions due to the lack of inversion symmetry give rise to a long-wavelength helimagnetic modulation, where wavelength of h is about 190Å. The propagation vector ~Q of the helix is pinned to the cubic spacediagonal by higher order spin-orbit coupling terms, which represent the weakest scale.

1. Ordered states with helical arrangement of the magnetic moments are described by a chiral order parameter which yields the left- or right-handed rotation of neighboring spins along the pitch of the helix.

2. Spins on a frustrated lattice form another class of systems, where simultaneous ordering of chiral and spin parameters can be found. Ex. triangular lattice with antiferromagnetic nearest neighbor interaction, the classical ground-state is given by a non-collinear arrangement with the spin vectors forming a 120◦ structure. In this case, the ground state is highly degenerate as a continuous rotation of the spins in the hexagonal plane leaves the energy of the system unchanged. In addition, it is possible to obtain two equivalent ground states which differ only by the sense of rotation (left or right) of the magnetic moments from sublattice to sub-lattice, hence yielding an example of chiral degeneracy.

3. CP breaking is the basic prediction of TGD and relates to the CP breaking of Chern-Simons action inducing CP breaking in the modified Dirac action defining the fermionic propagator. Chiral selection requires parity breaking, and the parity breaking of the molecule itself would induce the symmetry breaking if molecule possesses dark magnetic body., says Matti Pitkänen. I take my freedom to translate this magnetic body to the Dirac cone, (and it can also be seen as a wormhole?). DM-interaction depends on the polarization with respect to the magnetic vectors. The required asymmetry is a consequence of the cone, with one part dark, 'taking away' about half of the interacting particles, so that the effeciency of the reaction pathways can be much higher.

Water can be an interacting, reducing medium in this process. Conformal changes in proteins are also important as environmental influences. As are oxygen, of course, and other biomolecules.

4. Chiral fluctuations can be directly observed in non-centrosymmetric crystals without disturbing the sample by a magnetic field. polarized inelastic neutron scattering experiments performed in the paramagnetic phase of the itinerant ferromagnet MnSi that confirm the chiral character due to spin-orbit coupling. Antisymmetric (in forming the magnetic groundstate) and asymmetric interactions are possible.

Time can also be seen as a chiral structure?

5. There are a possibility for more than one mirror image, an hierarchy of particles can be created, but usually the other mirrorimages are dark (too low energy). TGD talks of an fractional quantum Hall effect.

Life as Islands.
Life is 'emergent'. It use the same atoms and molecules as rest of the matter, but maybe in one aspect Life is different. Life is built on hexagons. Life interact with the quantum world in many ways. It is important to keep that interaction at moderate levels, said Rakovic and Pitkänen, for organizational reasons.

One of the most fascinating aspects of physics is the 'emergence' of complex structures out of simple laws, an interesting case of which are structures protected by topological invariants. To illustrate an example of this, consider vortex lines in superconductors. In such systems, the phase of the Cooper-pair wave function rotates by 2πn as one circles a vortex. Continuity then requires the vorticity n to be an integer. For this reason, a vortex with n=±1 cannot decay.

Stabile topological structures lies behind biology. The stability are rationals, the oscillations are p-adics? The glue are entanglement in electon-sheets? Dirac-electrons are p-adics? One important task is to clearly define this interaction of stabilizating chaos. Life is complex.

TGD: The recent claim could be explained if antineutrinos and neutrinos in the experimental situation favor different p-adic primes p≈ 2k. If one has k(ν)=k(νbar)+1 for all families and the topological mixing matrices are otherwise the same (recall that fermion families correspond in the absence of mixing to different topologies for wormhole throats: sphere, torus, sphere with two handles, perhaps also higher families although there is good argument supporting the view that three lowest genera are "light").

Another kind of fraction is the cyclotrone resonance giving rise to molecular sensing?

The third one is the topological changes with distance and time? Then also the cognition, memory and the consciousness follows as a natural aspect.

Matti Pitkänen writes: A good guess is that algebraic entanglement is essential for quantum computation, which therefore might correspond to a conscious process. Hence cognition could be seen as a quantum computation like process, a more approriate term being quantum problem solving. Living-dead dichotomy could correspond to rational-irrational or to algebraic-transcendental dichotomy: this at least when life is interpreted as intelligent life. Life would in a well defined sense correspond to islands of rationality/algebraicity in the seas of real and p-adic continua.

Algebraic numbers are related to rationals by a finite number of algebraic operations (Gaussian distribution?) and are intermediate between periodic and chaotic orbits* allowing an interpretation as an element in an algebraic extension of any p-adic number field. The projections of the orbit to various coordinate directions of the algebraic extension represent now periodic orbits.

*) Chaotic orbits should be interpreted as potential possibilities?

The special nature of the Golden Mean, which involves 5^1/2, conforms the view that algebraic numbers rather than only rationals are essential for life. And may I fill in, spheres? One especially interesting aspect with this skyrmionic atomic model is that the Platonic solids are found directly from it.

The new secondary p-adic time scales assigned with elementary particles, in particular the .1 second time scale assignable with electron as time scale of corresponding "causal diamond" and defining fundamental biorhythm will mean a direct connection between living and dead matter. Time and entropy are so important for life to give the coherence. The chrystal phases is entanglement, or SOL-phases in biology.

Water, temp., pressure, pH etc. increases the 'noise' and hence the reactivity. Together with inhibition noise gives coherence in the different systems, so they can behave as entangled quantum dots, at least for a while. As instance when the chromophore is in excited state as opposite electronic ground state.

The basic prediction of zero energy ontology is that second law does not make sense in the time scale below the time scale defined by the temporal size of CD for physics associated with the field body of system in question - say electron, say Matti.

Complex structures are function of entropic/negentropic forces as amplified forces drive spatial expansion of matter. If this oscillation is a vortex the apex is also spiralling up. Stability = rationals, oscillation = complex numbers?

The gap opening is the window into the quantum world?

1. Condensed-matter physics: Single skyrmions spotted
Christian Pfleiderer & Achim Rosch: Nature Volume: 465,
Pages: 880–881 (17 June 2010) DOI: doi:10.1038/465880a

2. News. Dec 5, 2007 Tuneable gap semiconductor is a first Gapless semiconductor. http://physicsworld.com/cws/article/news/32085;jsessionid=34FB29F720E6613E9DC...

http://www.worldscibooks.com/physics/7397.html modelling of atomic nuclei.
http://www.springerlink.com/content/u6wl394757m80518/fulltext.pdf chlorophyll
http://physics.bu.edu/~neto/ quantum phase transition, theorists are being forced to revisit the conceptual basis for the theory of metals. http://arxiv.org/ftp/arxiv/papers/1003/1003.4520.pdf

3. Real-space observation of a two-dimensional skyrmion crystal
X. Z. Yu, Y. Onose, N. Kanazawa, J. H. Park, J. H. Han, Y. Matsui, N. Nagaosa & Y. Tokura
Nature 465, 901-904 (17 June 2010) | doi:10.1038/nature09124

4. MO-theory. Mark Bishop, http://www.mpcfaculty.net/mark_bishop/molecular_orbital_theory.htm http://arxiv.org/ftp/arxiv/papers/1001/1001.2021.pdf



fredag 18 juni 2010

A Great Day.

Today is a Great Day.

Finlands prime minister, Matti V. has redrew from his post. The story that began so good ended in misery. 7 years was enough. 7 is the number for completeness.

And the new prime minister is a lady, Mari K. Once I voted for a woman on the prime minister post, but she went into a trap, and was 'out of the game'. Old men couldn't stand the thought of a young woman, and clever, on the post.

Not so many countries in the world have women as both the president and the prime minister.

Matti fell on his affairs with women :) Roses have thorns, they can write books. Another minister, Ilkka, also fell because of his disgusting 'affairs' with women. An ex-minister for whom they have to warn young girls on the radio, not to start talking with. The latest 'affair' was 16 yers old. Sic.

Matti fell on his corruptedness. Finances in the last election isn't what they should be. It was such a long-going story that the police was visiting his house to look at some wood. And everybody wait for more small stories.

Matti fell because his party lost its trust in him. Preliminary counts show a popularity trend spiralling down.

Matti fell because of his lies. He was so unaware of how things were, he had such a bad memory.

Matti fell because of his arrogance. He became an enemy with the female president, when he wanted all power himself. Presidents has nothing to do in EU-top meetings.

Matti fell because of God knows what. But before he fell he had to fulfill a promise? So over-night he gave permission to two new nukes, one of which is german in the end. Today they discuss why we should build so many, when we don't need their electricity. Nobody has done those calculations properly. The situation was saved because someone found out the man who made the protest was disqualified. Matti could breath again. Let the germans come and exploate us. It is guaranteed for over 100 years. Who cares about the grandchildren?

I do care.

Today is a Great Day, because my second grandchild was born, a boy. So I believe in the future.

A very special boy. May God sign his head.

måndag 14 juni 2010

Simplicity - complexity. About condensed matter and topology.

In recent years dark matter (DM) interactions have attracted great interest, because they may stabilize magnetic structures with a unique chirality and non-trivial topology. The inherent coupling between the various properties provided by DM interactions is potentially relevant for a variety of applications. The, perhaps, most extensively studied material in which DM interactions are important is the cubic B20 compound MnSi, the magnetic field and pressure dependence of the magnetic properties of MnSi. At ambient pressure this material displays helical order. Under hydrostatic pressure a non-Fermi liquid state emerges, where a partial magnetic order, reminiscent of liquid crystals, is observed in a small pocket. Recent experiments strongly suggest that the non-Fermi liquid state is not due to quantum criticality. Instead it may be the signature of spin textures and spin excitations with a non-trivial topology.

Zaanen has written a short popular paper about why this superconduction is interesting. Well worth reading.

About the Condensed Matter Theory Group
The theory group conducts basic research over a wide swath of theoretical physics, ranging from strongly correlated electrons to first principle electronic structure theory to the statistical mechanics of complex systems. Elastic and inelastic neutron scattering techniques are used to study cooperative phenomena in complex solids.

High-Tc materials that carry current with no resistance is one field of research. The scientists looked for changes in the magnetic response over a range of temperature, from the non-superconducting state to below the transition temperature (Tc) where the material becomes a superconductor. Unlike the dramatic changes observed in electronic behavior as the material is cooled below the transition temperature, there were only minor changes in magnetic behavior.

This finding challenges the validity of the most popular theoretical models currently used to predict magnetic properties from electronic measurements.
“If the dual existence of localized and free-flowing electrons is important, we want to look for other materials that have those characteristics, but transition to superconductivity at even higher temperatures,” Tranquada said. From the article:

“The calculations based on the material’s electronic properties — which change dramatically as the material is cooled and transitions from its electrically resistive state to become a superconductor — predicted there would be a similar large change in magnetic characteristics below the transition temperature (Tc),” said Brookhaven physicist Guangyong Xu. “But our direct measurements of the magnetic properties showed surprisingly little change. This implies that the model the theorists have been using to describe these magnetic properties is incomplete.”

It’s not that the magnetic properties are completely unrelated to the electronic properties; they are both still part of the same system, the scientists emphasize. Magnetism, after all, comes from the relative arrangements of the directions in which electrons spin, like a collection of tiny bar magnets.

“It could be that the magnetism somehow drives the electronic structure, rather than the other way around — or that something underlying both magnetism and electronic structure influences both but in different ways,” Xu said.

“You can think of it as the foreground and the background of a painting,” Tranquada suggested. “We are interested in the superconductivity, which is what stands out — the foreground. And we know electrons are involved in that by pairing up to carry current with no resistance. But are those same electrons defining the magnetic properties? Or do other, ‘background’ electrons define the magnetism?”

The magnetic measurements showed that some of the magnetic characteristics of the original “parent” compound — which is an insulator — remain when the material becomes a superconductor. This suggests that there may be two kinds of electrons: some moving around like waves to carry the current while others remain in relatively fixed positions to produce the magnetism.

The heavy fermion phenomenon is found in a wide variety of materials - mostly metals combined with rare-earth elements - in which there is a periodic array of atoms that have a magnetic moment. Many heavy-fermion materials can become superconductors at very low temperatures, a puzzler because magnetism and superconductivity usually don't coexist. Electrons moving through a particular uranium compound appear "heavy" because their motion is constantly interrupted by interaction with the uranium atoms.

For decades physicists have been fascinated and frustrated by "heavy fermions" - electrons that move through a conductor as if their mass were up to 1,000 times what it should be. URu2Si2, composed of uranium, ruthenium and silicon, was examined. At about 55 kelvins (degrees above absolute zero, -273 degrees Celsius), it begins to show heavy fermion behavior. At 17.5 kelvins it goes through a complex phase transition in which its conductivity, ability to absorb heat and other properties change. Theorists attribute this to a "hidden order" in the material's electrons, but what that might be remained a mystery. mobile electrons in the sample, rather than flitting lightly from atom to atom, were interacting strongly with the uranium atoms, in effect diving down into their lower energy levels for picoseconds. This confirms a theoretical explanation for the heavy fermion phenomenon that electrons, which have a tiny magnetic moment, interact with the magnetic moments of uranium atoms. They are not really "heavy," but move as if they were.

Spectroscopic imaging scanning tunneling microscopy reveals a "hidden order" of electrons, seen as bright areas, within uranium ruthenium silicate as it is cooled to very low temperatures. Seeing this hidden order for the first time has unraveled a 25-year-old physics mystery. A video here.

"People know about high-spin molecules, but no one has been able to bring together the chemistry and physics to make controlled contact with these high-spin molecules," Dan Ralph said. The work is published in the June 10 online edition of the journal Science. First author is Joshua Parks, a former graduate student in Ralph's lab.

The researchers made their observations by stretching individual spin-containing molecules between two electrodes and analyzing their electrical properties. They watched electrons flow through the cobalt complex, cooled to extremely low temperatures, while slowly pulling on the ends to stretch it. At a particular point, it became more difficult to pass current through the molecule. The researchers had subtly changed the magnetic properties of the molecule by making it less symmetric.

After releasing the tension, the molecule returned to its original shape and began passing current more easily - thus showing the molecule had not been harmed. Measurements as a function of temperature, magnetic field and the extent of stretching gave the team new insights into exactly what is the influence of molecular spin on the electron interactions and electron flow. See pictures here.

Effect of covalent bonding on magnetism and the missing neutron intensity in copper oxide compounds, letter to Nature, 2009. Walker et al. says:
However, the absolute intensities of spin fluctuations measured in neutron scattering experiments vary widely, and are usually much smaller than expected from fundamental sum rules, resulting in ‘missing’ INS intensity. Magnetic excitations in the one-dimensional related compound, Sr2CuO3, for which an exact theory of the dynamical spin response has recently been developed. In this case, the missing INS intensity can be unambiguously identified and associated with the strongly covalent nature of magnetic orbitals. We find that whereas the energies of spin excitations in Sr2CuO3 are well described by the nearest-neighbour spin-1/2 Heisenberg Hamiltonian, the corresponding magnetic INS intensities are modified markedly by the strong 2p–3d hybridization of Cu and O states. Hence, the ionic picture of magnetism, where spins reside on the atomic-like 3d orbitals of Cu2+ ions, fails markedly in the cuprates.

So magnetism isn't what it should either? Normally to keep things simple, to describe the magnetism of the copper atoms, people tend to use a spin distribution based on isolated copper atoms. But in reality, the spin density must be spread out along the strong copper-oxygen covalent bonds that are part of the structure of the material and which are responsible for the remarkable magnetic properties in the first place.

Now the team has shown how to correctly compare theoretical models to experimental data, they are hoping that the hunt for the answer to high-temperature superconductivity in the cuprate materials can be reached more quickly.

It is widely believed that the magnetism of the copper atoms, which as this study shows is that of copper-oxygen covalent complexes, plays a vital role in superconductivity.

Disappearing Superconductivity Reappears - in 2-D. Scientists studying a material that appeared to lose its ability to carry current with no resistance say new measurements reveal that the material is indeed a superconductor — but only in two dimensions. Equally surprising, this new form of 2-D superconductivity emerges at a higher temperature than ordinary 3-D superconductivity in other compositions of the same material. Publ.in the November 2008 issue of Physical Review B.

A hard-to-detect form of superconductivity occurs?
Tranquada and his colleagues have been studying a layered material made of lanthanum, barium, copper, and oxygen (LBCO) where the ratio of barium to copper atoms is exactly 1 to 8, and at the mysterious 1:8 ratio, the transition temperature at which superconductivity sets in drops way down toward absolute zero. At a particular temperature, a big drop was seen in resistance when the current was flowing parallel to the layers, but not when it was flowing perpendicular to them. At the same time they measured the onset of weak “diamagnetism,” an effect in which magnetic fields are pushed out of the sample. “This is one of the key properties of a superconductor — the Meissner effect.” Like the drop in resistance, the Meissner effect occurred in only two dimensions, within the planes. There is a subtle form of superconductivity confined within the two-dimensional planes, For some reason the material is unable to coherently couple that superconductivity between the planes.

This material exhibits another interesting property: an unusual pattern of charge and magnetism known as “stripes,” which many theorists have long assumed was incompatible with superconductivity. Stripes find their origin in the microscopic quantum fluctuations?

Stripe order in the copper oxide planes involves both a modulation of the charge density (blue), detectable with x-ray diffraction, and a modulation of the arrangement of magnetic dipole moments (spin directions) on copper atoms (magenta arrows)from Tranquada group.

A power point talk here. Resonance is about spin. Dynamic spin promote and static spin destroys superconductivity. More static spins means less dynamic spins.

Asymmetric superconducting domes in the phase diagram, due to an electron-hole asymmetry in the Fermi surface (FS) and nesting condition due to di fferent e ffective masses for di fferent FS sheets. This built-in EHA from the band structure, which matches well with observed asymmetric superconducting domes in the phase diagram, strongly supports FS near-nesting driven superconductivity in the iron pnictides. The band structure undergoes unconventional band folding that leads to the formation of Dirac cones?, says Neupane et.al.

Our results suggest that spin fluctuations associated with the collinear magnetic
structure appear to be universal in all Fe-based superconductors, and there is a strong correlation between superconductivity and the character of the magnetic order/fluctuations in this system. says Xu et al.. Our results suggest that static magnetic order exists in all non-superconducting samples. The proper tuning of these correlations may be the key for enhancing superconductivity.

Relaxors is the name given to a special class of materials called relaxor ferroelectrics. The hallmark of relaxors is a highly frequency-dependent dielectric response that peaks broadly at a temperature that is unrelated to any structural phase transition.Video here.
Why do relaxors have such an exceptional electromechanical response. The explanation is dependent on "polar nanoregions" - tiny, nanometer-scale regions within the relaxors. The team established a link between polar nanoregions and the relaxors' ability to deform in response to an electric field, or to have a pulse of electric current induced by a deforming physical force.
The chemical short-range order in these materials, which are primarily compositionally disordered oxides, plays probably a key role in determining the bulk response. Dielectric Raman scattering, and piezoelectric force have been used to explore the behavior, and also diffuse scattering, which reflects the presence of short-range ordered, atomic displacements. Then there are revealed another diffuse scattering through its dependence on an oriented electric field. When studying relaxor systems, the existence of complex nano-scale polar structures will have to be carefully taken into consideration; indeed, these may affect the lifetimes of phonons propagating along these two sets of directions.

While the spin resonance occurs at an incommensurate wave vector compatible with nesting, neither spin-wave nor Fermi-surface-nesting models can describe the magnetic dispersion. We propose that a coupling of spin and orbital correlations is key to explaining this behavior. If correct, it follows that these nematic fluctuations are involved in the resonance and could be relevant to the pairing mechanism. Such a coupling has already been proposed for the antiferromagnetic phase.

Can spontaneous symmetry breaking play a role in a dynamical reduction of quantum physics to classical behavior? The surprising outcome that spontaneous symmetry breaking imposes a fundamental limit to the time that a system can stay quantum coherent. What does all of this have to do with the dynamical phenomenon of decoherence? Decoherence refers to the fact that the quantum information encoded in some microscopic state entangles in the course of its time evolution with environmental degrees of freedom. The crucial point is that spontaneous symmetry breaking is intrinsically linked to the presence of a spectrum of 'environmental states.' In a rigorous fashion, the quantum information carried by these states cannot be retrieved when the body is macroscopic. To what extent can this thin
spectrum be a source of decoherence, intrinsically associated with the fact that quantum measurements need classical measurement machines.

Topology forms stability.
Spin-orbit coupling causes novel forms of electronic organization that can be
captured by topology, says Zaanen, 2009 and do not change upon deformation. The so far most complex form of magnetic order observed: In the presence of a magnetic field,
the electron spins in manganese silicide (MnSi) form a lattice of topological “particles” called skyrmions. The spins form a hexagonally closest packed arrangement of topologically stable knots parallel to an applied magnetic field. However, these patterns now occur in the space of wave vectors of the electron wave functions associated with this metallic surface. Their shapes and topology are dictated by a bulk insulating state. Unlike ordinary insulators, this bulk is a macroscopic object that carries a net quantum entanglement. In the quantum world where every state is influenced by every other state in a way that has no counterpart in the realm of everyday experience. This bulk entanglement in turn dictates how the surface quantum states are linked together.
The aspect of relativity that matters for spin-orbit coupling is the unification of electricityand magnetism by the principle of relative motion. When a magnetic dipole, such as the electron spin, moves relative to an electrical field at rest, it experiences the latter as a magnetic field, that also maximizes magnetic ordering. Such helical magnetism forms spontaneously. However, when a magnetic field is applied (between 0.1 and 0.2 T), a mysterious “A phase” is found. It is the “skyrmion lattice”. The reasons for its stability are complicated and include help from thermal fluctuations, but the key feature is that the red regions in panel B of the figure (the skyrmions) crystallize as if they were atoms. Topology forms in vectors that can point in arbitrary directions in space, such as the magnetization of MnSi. The magnetic order forms topological knots, skyrmions.

Skyrmions represent topologically stable field configurations with particle-like properties. The spontaneous formation of a two-dimensional lattice of skyrmion lines, a type of magnetic vortex, in the chiral itinerant-electron magnet MnSi. The skyrmion lattice stabilizes at the border between paramagnetism and long-range helimagnetic order perpendicular to a small applied magnetic field regardless of the direction of the magnetic field relative to the atomic lattice. Mühlbauer et. al 2009 experimentally establishes magnetic materials lacking inversion symmetry as an arena for new forms of crystalline order composed of topologically stable spin states.

Physics wievpoint. A skyrmion in a two-dimensional magnet. The small arrows represent the magnetization direction. The magnetic field B is applied in the upwards direction. For skyrmion lines in a three-dimensional magnet, as suggested by recent Hall effect measurements for MnSi, this pattern describes the magnetization in planes perpendicular to B.

The Hall effect in MnSi contains contributions besides the ordinary Hall effect: the anomalous and topological Hall effects. The anomalous Hall effect is due to the nonvanishing average magnetization in an applied magnetic field. Neubauer et al. [1] observe another contribution to the Hall effect that is sharply restricted to the A phase. They show that a lattice of skyrmion lines would lead to a topological Hall effect, which can be described by an effective magnetic field proportional to the concentration of skyrmions. The observed contribution has the predicted magnitude and sign, strongly supporting the skyrmion picture for the A phase. But also the pressure invokes.

Many years ago Skyrme showed that topologically stable objects of a nonlinear field theory for pions can be interpreted as protons or neutrons. Twenty years ago it has been predicted that skyrmions exist in anisotropic spin systems with chiral
spin-orbit interactions, where they are expected to form crystalline structures.

If correct, this would imply that nematic excitations are a key feature of the normal state from which the superconductivity develops.

Entanglement refers to the “spooky” quantum phenomenon that correlates the information in quantum states together in ways that make it possible to compute exponentially faster than with classical states; this is the idea behind quantum computing. Typically, only a few microscopic degrees of freedom can be entangled because under normal circumstances, the contact with the classical macroscopic world will destroy the entanglement long before the quantum system itself becomes macroscopically large. However, topological effects help protect its net entanglement
against collapse. These can be viewed as an electronic “nothingness” that is quite akin to the fundamental vacuum of the Dirac theory. This “insulating nothingness” can have topological structure. The quantum entanglements of all occupied electron states can combine in one overall topological quantity, forming the “topological insulator” that carries a global entanglement. The electrodynamics of topological insulators is also quite strange: When an electrical charge is brought to the surface, it will bind automatically to a magnetic monopole formed in the bulk, and this “dyon” should behave like particle with fractional quantum statistics. Alternatively, when a superconductor is brought into contact with a topological insulator, its magnetic vortices are predicted to turn into particles that can be used for topological quantum computing.

Zero point energy field, zero energy ontology.
Zero-point field is sometimes used as a synonym for the vacuum state, the energy of the ground state. In cosmology, the vacuum energy is one possible explanation for the cosmological constant.
Zero energy ontology is used in TGD. "In zero energy ontology positive and negative energy states correspond to infinite integers and their inverses respectively and their ratio to a hyper-octonionic unit. The wave functions in this space induced from those for finite hyper-octonionic primes define the quantum states of the sub-Universe defined by given CD (cone) and sub-CDs (hierarchy). These phases can be assigned to any point of the 8-dimensional imbedding space M8 interpreted as hyper-octonions so that number theoretic Brahman=Atman identity or algebraic holography is realized!"

In topological surface state on 3D topological insulator, the electrons obey the 2D Dirac equations. Since the surface state of topological insulator has a suppressed backward scattering for nonmagnetic impurities, this is a promising material for designing the quantum curcuit. Therefore, electric control of transport on the surface of topological insulator is an important issue. In fact, the chiral edge channels are predicted to appear at the interface of two ferromagnets with magnetization along z and −z directions, i.e., perpendicular to the surface. The energy dispersion of these states is almost linear in the momentum with the velocity sensitively depending on the strength of the gate voltage. The energy is also restricted to be positive or negative depending on the strength of the gate voltage. Consequently, the local density of states near the gated region has an asymmetric structure with respect to zero energy.
Dirac fermions in solids. In 2005 experiments on graphene, a single layer of carbon atoms, were first reported. These exhibited exotic physical properties such as a universal minimum conductivity and an anomalous integer quantum Hall effect. These phenomena are due to the fact that the hexagonal lattice of graphene exhibits two Dirac points with a linear dispersion relation, which lead to a long-wavelength description in terms of massless Dirac Fermions.

This has led to the question as to how the Kondo effect, the local screening of f-moments by the conduction electrons, gets destroyed as the system undergoes a phase change. In one approach to the problem, Kondo lattice systems are studied through a self-consistent quantum impurity problem, the Bose-Fermi Kondo Model (BFKM). This approach has been termed the Extended Dynamical Mean Field Theory (EDMFT)
Mapping of the Kondo lattice model onto an effective quantum impurity model augmented with self-consistency conditions within the extended dynamical mean field theory.

Seamus Davis and John Tranquada together with Aharon Kapitulnik (Stanford) have been honoured with the 2009 Heike Kamerlingh Onnes Prize for outstanding superconductivity experiments. Named after the winner of the 1913 Nobel Prize in physics for the discovery of superconductivity and related research, the Onnes Prize is awarded every three years for outstanding experiments that illuminate the nature of superconductivity – the disappearance of electrical resistance in certain materials at specific temperatures, mostly in the range of nearly absolute zero. The basic idea behind superconductivity is that electrons, which ordinarily repel one another because they have like charges, pair up to carry electrical current with no resistance. Future room-temperature devices would make this cheap.