1,816 reputation
415
bio website
location Santa Barbara, CA
age 27
visits member for 2 years, 5 months
seen Jul 15 at 10:37

I am a postdoc at Kavli Institute for Theoretical Physics, University of California, Santa Barbara. My major is in condensed matter physics.


Jul
2
awarded  Curious
Jun
27
awarded  Revival
Jun
17
comment Matsubara Frequencie
I would suggest you read Wikipedia (en.wikipedia.org/wiki/Matsubara_frequency) before asking.
May
28
comment Two-Dimensional Tight-Binding Dispersion Relation
You are wrong at your second equality, where $\delta_{k_{1x}k_{2x}}$ should be $\delta_{k_{1}k_{2}}$. You can obtain the right result just because you are wrong again at your third equality.
May
23
comment Solving the BCS Hamiltonian via the Bogoliubov Transformation
I do not see how you can possibly arrive at $\sqrt{\xi^2+V^2}+\xi$. Just remind that the last term $\sum_k\xi_k$ is the vacuum energy, which does not enter either the spectrum or the quasiparticle excitation energy. In any case the spectrum should be $\sqrt{\xi^2+V^2}$ without the additional $\xi$.
Apr
6
comment What is an electron/hole pocket and what is the significance?
Yes, the reduced BZ's can be labeled by band index $n$ if there is only a single site in the unit cell. But we do not care this index very much. I don't think it will make any difference if the electron pocket is coming from the 14th BZ instead of the 4th. All the bands that are fully filled below the Fermi energy are irrelevant to low-energy physics. The only band we care about is the highest band, where the Fermi surface rest in. The Fermi pockets are just the Fermi surface in this highest band.
Apr
6
answered What is an electron/hole pocket and what is the significance?
Apr
4
answered Why can't a dislocation terminate in the bulk?
Apr
4
comment How to conclude that an interaction is attractive from its Fourier transform (momentum space representation)?
@RobinEkman No, please forget about anything in the real space, it is totally irrelevant. The sign of A at a particular momentum tell us nothing about the sign of A in the real space. Even if A is positive in the real space, and even A has a local maximum at 0 distance, we can still say that the interaction is attractive at some particular momentum and frequency! And this is the point indeed: the electron-electron interaction is repulsive in the real space, but in the momentum space, the same interaction can be attractive at some particular momentum!
Apr
2
comment Understanding Elitzur's theorem from Polyakov's simple argument?
@VanillaSpinIce Because the expectation values of the operator that is not gauge invariant would correspond to the "name" that we use to label the state. As emphasized by Prof. Wen, the name is not a physical observable, all names are equivalent in the gauge theory. Any expectation value of such operator will single out one name from the others, which is illegal.
Apr
2
revised Understanding Elitzur's theorem from Polyakov's simple argument?
typset ket states
Apr
2
suggested suggested edit on Understanding Elitzur's theorem from Polyakov's simple argument?
Apr
2
answered How to conclude that an interaction is attractive from its Fourier transform (momentum space representation)?
Mar
15
comment String-net models on non-trivalent lattices
@MrLee Even if the graph is directive, you can still combine sites to make non-trivalent graphs, just remember to keep the link direction unchanged. I can see your concern, the directive graph is indeed more complicated, for example you can not rotate the graph, and you also need to take care of the bending. On a non-orientable manifold you may not even be able to assign the directions. But if you already start from a well-defined directive trivalent graph, there is no ambiguity.
Mar
15
answered String-net models on non-trivalent lattices
Mar
11
asked Why is there a Majorana zero mode in the $\pi$ flux core of the p+ip superconductor?
Feb
24
comment How to determine the orientation of the massive Dirac Hamiltonian?
@K-boy Yes, you need to define which mass is called positive. If you flip the sign of the mass, the Chern number will also flip the sign. The chirality of your Dirac Hamiltonian is only defined if the fermion is gapped, then the sign of the mass is a mater of how you choose to gap the system.
Feb
24
answered How to determine the orientation of the massive Dirac Hamiltonian?
Feb
24
answered How to derive the Aharanov-Bohm effect result?
Feb
24
answered Difference between charge density wave and charge distribution