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Concepts of Berry curvature and Chern number are key to make a difference between what is topological and what it is not. Let's consider an hamiltonian $\mathcal{H}$ which is a function of N time-dependant parameters $(\Gamma_1(t)\,...\,\Gamma_j(t)...\,\Gamma_N(t))\equiv\mathbf{\Gamma}(t)$. The evolution of such system is given by the Schrödinger equation : ...


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Strong correlation usually come with localized $d$ or $f$ orbitals in (or close to) a Mott insulating state, where the charge degrees of freedom is gapped by interaction, and the system become insulating even at half-filling. Silicon has no localized orbitals and it is a band insulator. Its valence band is fully filled, not half-filled, which means it can ...


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The fluid in the tube is not water as some might think but an organic solvent called Dichloromethane. The reason the bubbles form is due to the fact that the fluid is heated at the base of the tube to it's boiling point which is a low 103.3 F degrees. You can almost get it boiling by holding it in your hand. The bubble is actually the vapor form of the ...


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I believe that the math covering condensed matter physics are very similar to that describing black holes and some high energy physics. So what was seen was an experimental result verifying the maths. Whether the maths really applies to a BH is unknown. In a way, it is more like solving equations experimentally using condensed matter as an analog computer. ...


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I would just like to point out that the given Hamiltonian does not require a Bogoliubov transformation to be diagonalized, since it is of the form of a single-particle operator (nevertheless in second quantization) i.e. does not contain 'off-diagonal' terms of the form $a a$,... You can simply diagonalize it by diagonalizing the coupling matrix. @leongz: ...


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Personally, I find it more intuitive to think in terms of the closely related quantity, the loss function, $-\text{Im}\frac{1}{\epsilon}$, rather than the optical conductivity. If one were to tune across a phase transition from a electronic liquid to an electronic solid, I suspect one would expect to see the softening of the free-carrier plasmon. Once the ...


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Yes there are. Among normal matter, only solids and liquids can sustain negative pressure. For solids we can shape the material like a 3D cross and pull in three directions at once. We can also do it in lqiuids. Here is a discussion for negative pressure, as in below-vacumn pressure, in liquids: http://discovermagazine.com/2003/mar/featscienceof This is ...


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To answer your question, one needs to understand a bit what is the Ginzburg-Landau (GL) formalism. Let us first recall the GL functional: $$F=\int dV\left[g\left|\left(\nabla-\dfrac{2\mathbf{i}e}{\hbar}A\right)\Psi\right|^{2}+a\left(T-T_{c}\right)\left|\Psi\right|^{2}+b\left|\Psi\right|^{4}+\dfrac{\left(\nabla\times A\right)^{2}}{2\mu}\right]$$ with ...


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This issue is a well known problem in high energy physics which is called " Neutrino Billiards". You can find a full description about it in: Ref: Berry, M.V. and R.J. Mondragon, Neutrino Billiards: Time-Reversal Symmetry-Breaking Without Magnetic Fields. Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences, 1987. 412(1842): p. ...


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Recall that the Fermi surface of the free electron gas, the total momentum is zero. How can electron gas be conductive? Well, when you apply the electric field, it will be non zero. The story is same for superconductivity.


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You don't have to discretize your problem (XY model). For each step, just take some value as the new $\theta$, and calculate the transition rate accordingly. Of course, when choosing the new value of $\theta$, better don't do it in a completely random way, otherwise your transition rate might be usually too small and you are just wasting time. Having said ...


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There was a recent publication addressing exactly this question. From the abstract: Here, we show that the overall foaming-over process can be divided into three stages where different physical phenomena take place in different time scales: namely, the bubble-collapse (or cavitation) stage, the diffusion-driven stage, and the buoyancy-driven stage.



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