The spin-model tag has no wiki summary.
2
votes
1answer
161 views
Why we call the ground state of Kitaev model a Spin Liquid?
Now we always talk about the so-called Kitaev spin liquid. One important property of spin liquid is global spin rotation symmetry. Let $\Psi$ represents a spin ground state, if $\Psi$ has global spin ...
2
votes
1answer
271 views
A simple model that exhibits emergent symmetry?
In a previous question Emergent symmetries I asked, Prof.Luboš Motl said that emergent symmetries are never exact. But I wonder whether the following example is an counterexample that has exact ...
1
vote
1answer
253 views
Long Range Spin-Spin Interactions
A recent article on probing Earth's interior mentioned the potential use of a "fifth force", long range electron spin-spin interactions, as a tool in the endeavor.
Has anybody published any ...
2
votes
1answer
67 views
What is the physical meaning of this simplification to calculate the effective coupling constants for a Gaussian model with quartic interactions?
To calculate the effective coupling constants $u'_2(q)$ and $u'_4(q)$ of the effective Hamiltinian eq (4.9) of this paper
$$ H' = -\frac{1}{2}\int\limits_q u'_2(q)\sigma'_q\sigma'_{-q}
- ...
6
votes
0answers
41 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 ...
3
votes
1answer
75 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 ...
8
votes
1answer
81 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 ...
3
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2answers
99 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. ...
7
votes
1answer
69 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, I've ...
9
votes
0answers
55 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 ...
13
votes
1answer
78 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
$$
...
12
votes
3answers
82 views
Visualization of 1D spin chain wave fuction
What are the known methods for visualizing quantum states of one-dimensional spin chains? They can be based either on their wave functions or density matrices.
My particular interest is in plotting ...
22
votes
1answer
197 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 hard-core ...
