7 votes

Since anyons cannot exist in our 3+1D world, what does it mean to have discovered them? Why should we study them?

The short answer is that no, you will in principle never run into issues describing your system with only fermions and bosons, as physical reality indeed only consists of these two particles. Whether ...
Codename 47's user avatar
  • 2,361
3 votes

Is there a blackbody spectrum of photons inside a solid?

In thermal equilibrium there are definitely photons inside a solid. They're bosons, so they will be described by the Bose-Einstein distribution. But they won't necessarily have a "blackbody ...
knzhou's user avatar
  • 102k
2 votes
Accepted

Can the hybridization of edge states in the 1D SSH model be observed numerically?

To answer point 1, you should look at the eigenvalues for those two modes: They should be very close, but not the same. This might very likely also answer 2 -- the hybridization should go down ...
Norbert Schuch's user avatar
1 vote
Accepted

Delocalized electrons in the Hubbard model for Mott insulators

'The Hubbard model is an approximate model used to describe the transition between conducting and insulating systems.' (Wikipedia) It does so by considering two parameters, the hopping term t and the ...
my2cts's user avatar
  • 23.8k
1 vote
Accepted

Why acoustic phonon dispersion cross $\omega=0$ at $k=0$?

For the acoustic mode, $k=0$ means all lattice points oscillate in phase. But still, they are oscillating so each lattice point must have some finite frequency (otherwise they would hold still or ...
hft's user avatar
  • 18.9k
1 vote

What is the meaning of screened potential?

why do we need another potential besides the Coulomb one that includes the interaction between every particle in the system? The problem is that we can not solve the problem if we include all the ...
hft's user avatar
  • 18.9k
1 vote

What is parity of charge?

Charge parity conservation means that charge is conserved modulo 2. This is because of the $\mathbb{Z}_2$ nature of the symmetry (as opposed to usual $U(1)$). Another way to see this is that by ...
Nandagopal Manoj's user avatar
1 vote

Why aren't completely random quantum states 'physical'?

The statement "Completely random states are generically not physical" only makes sense in a very specific context. An obvious counter example being the totally mixed state $\rho=I/d$ being &...
Jun_Gitef17's user avatar
1 vote

Understanding the left-canonical matrix product state

Let us work through your example, i.e., $2^6$-dimensional normalized complex vector $|\psi\rangle$ \begin{equation} |\psi\rangle=\sum_{\sigma_1,\sigma_2,\ldots,\sigma_6}\psi_{\sigma_1,\sigma_2,\ldots,\...
Adam's user avatar
  • 31
1 vote

$\mathbf k\cdot\mathbf p$ Hamiltonian

I am not sure what $P_{cv}(k)$ and $C(s)$ are without some more context, but we can work through the $k\cdot p$ model from the beginning and continue the dialogue if you're still unsure. $k\cdot p$ ...
intraband's user avatar
1 vote

What is topological about topologically ordered states?

Topological order, by definition, describe the internal order of gapped liquid state of a lattice model that does not have any symmetry (0-form, higher-form, or non-invertible). More precisely, two ...
Xiao-Gang Wen's user avatar
1 vote

Why the symmetry is not $Pin(1,3)$ or $Pin(3,1)$ in condensed matter physics?

Here is the answer from myself. The group $Pin(1,3)$ has group elements time reversal $T$ and reflection $M_i$ along 3 spatial axes such that $T^2=1$, $M_i^2=-1$ and $TM_i=-M_iT$, $i=x,y,z$. Similarly,...
edittide's user avatar
1 vote
Accepted

Sublattice Magnetization of Heisenberg Model on triangular lattice

Why does no SSB in finite systems imply we have to look at $\hat m_z^2$ instead of $\hat m_z$? This is a common point to get confused about SSB. To really understand it, you would actually need to ...
Jun_Gitef17's user avatar
1 vote

How the $-2t\cos(k)$ term appears in the dispersion of the $1D$ tight binding model?

I guess it won't be important anymore but I still would like to clarify: I guess you are refering to the beginning of page 6. The step you are confused of is not using the commutator relations of ...
ChrisG's user avatar
  • 11

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