All Questions
7
questions
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Tunneling lowers the energy of a ground state superposition of spins up and down in the quantum Ising model
Considering an Ising model in the quantum scenario in quantum spatial dimension d=1 (that corresponds to classical D=2=d+1 dimension). Starting with the Ising model hamiltonian under the approximation ...
- 310
2
votes
1
answer
676
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Transverse-field Ising model in the presence of a longitudinal field - ferromagnetic phase diagram
I am wondering what is the phase diagram of the transverse-field Ising model in the presence of a longitudinal field, in particular, a one-dimensional spin-1/2 chain with ferromagnetic interactions. ...
- 21
0
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120
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Quantum Monte Carlo Loop Algorithm for quantum spin: why is the freezing graph present in ferromagnetic Ising model?
I study the loop algorithm (Evertz et al).
I cannot understand, why the freezing graph type where we have to flip all 4 spins together is not present for the quantum-XY model and the anti-/...
- 115
1
vote
0
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494
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Practical/experimental difference between (quantum) Heisenberg and (classical) Ising model
I have read a few discussions about the difference between the Heisenberg model (using quantum spin operators) and Ising model (with spins $\pm 1$), notably this one or this Quora post.
All the ...
- 119
17
votes
2
answers
1k
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What is the momentum canonically conjugate to spin in QM?
In Kopec and Usadel's Phys. Rev. Lett. 78.1988, a spin glass Hamiltonian is introduced in the form:
$$
H = \frac{\Delta}{2}\sum_i \Pi^2_i - \sum_{i<j}J_{ij}\sigma_i \sigma_j,
$$
where the ...
- 321
8
votes
2
answers
358
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Is there a spin glass version of Prince Rupert's Drop?
Spin Glasses are known to converge to their ground state under Simulated Annealing.
The word choice is especially interesting since annealing is also the name of a process performed on actual glass. ...
- 4,841
5
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1
answer
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Some limiting cases of the Heisenberg XXZ model (2/2)
NOTE: Because this was a long question I have split it up in two different questions!
For a course on quantum integrability I am reading these notes.
(Franchini: Notes on Bethe Ansatz Techniques. ...
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