All Questions
Tagged with spin-models research-level
12
questions
1
vote
0
answers
89
views
How does the Kalmeyer-Laughlin argument work?
I want to ask about the argument in the Kalmeyer-Laughlin paper that connects the Heisenberg Hamiltonian to a quantum Hall one. I know there is a related question about the same paper. My question is ...
- 53
0
votes
0
answers
31
views
How to get algebraic PSG solutions once we got the constraints?
The question is more technical than conceptual. I've been trying to understand the classification of spin liquids as done by Prof.Wen. I have got the constraints on IGG(Invariant gauge group) elements ...
7
votes
1
answer
4k
views
Ground state degeneracy: Spin vs Fermionic language
Let us first consider the Hamiltonian of well-known 1D periodic Ising model as
$$
H = -\frac{1}{2} \sum_{j=1}^N \sigma^x_j \sigma^x_{j+1} + \frac{h}{2}\sum_{j=1}^N \sigma^z_j.
$$
Now, in the ...
- 173
4
votes
0
answers
329
views
Chiral spin liquid flux states on the Kagome lattice
Short version:
Is it possible to arrange the fluxes for the Kagomé lattice with triangle flux $\phi_\triangle=\frac{\pi}2$ and hexagon flux $\phi_{hex}=0$ using a single unit cell?
Longer version:
I ...
- 167
8
votes
0
answers
166
views
Do bipartite spin glasses have simple relaxation dynamics?
From what I gather, a Boltzmann machine (BM) is essentially a spin glass with no applied field evolving under Glauber dynamics (if this is at all mistaken, I don't think it will be off enough to ...
- 351
3
votes
1
answer
396
views
Random bond Ising model and computational efficiency
If you want to find the ground state of the 2d random bond Ising model (no field), a computationally efficient algorithm exists to do it for you (based on minimum weight perfect matching). What about ...
- 695
9
votes
1
answer
113
views
Many body quantum states analyzed as probabilistic sequences
Measurements of consecutive sites in a many body qudit system (e.q. a spin chain) can be interpreted as generating a probabilistic sequence of numbers $X_1 X_2 X_3 \ldots$, where $X_i\in \{0,1,\ldots,...
- 6,480
5
votes
2
answers
392
views
Do any entanglement measures for mixed states exist that use only single site correlation functions?
For a pure state $\rho_{AB}$, the entropy of entanglement of subsystem $A$ is
\begin{equation}
S( \rho_A) = -tr (\rho_A \log \rho_A)
\end{equation}
where $\rho_A$ is the reduced density matrix of A. ...
- 885
9
votes
1
answer
351
views
How does one geometrically quantize the Bloch equations?
I've just now rated David Bar Moshe's post (below) as an "answer", for which appreciation and thanks are given.
Nonetheless there's more to be said, and in hopes of stimulating further posts,...
John Sidles
24
votes
1
answer
470
views
Fluctuations of an interface with hammock potential
This question is related to that one. I ask it here since comments are too short for the extended discussion that was going on there.
I am interested in a very simple interface model. To each $x\in\...
- 10.4k
17
votes
1
answer
609
views
Phase Transition in the Ising Model with Non-Uniform Magnetic Field
Consider the Ferromagnetic Ising Model ($J>0$) on the lattice $\mathbb{Z}^2$ with the Hamiltonian with boundary condition $\omega\in\{-1,1\}$ formally given by
$$
H^{\omega}_{\Lambda}(\sigma)=-J\sum_{...
Leandro
26
votes
1
answer
1k
views
Mermin-Wagner theorem in the presence of hard-core interactions
It seems quite common in the theoretical physics literature to see applications of the "Mermin-Wagner theorem" (see wikipedia or scholarpedia for some limited background) to systems with ...
- 10.4k