All Questions
Tagged with spin-models quantum-spin
86
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How to compute the MPS representation for a sequence of asymptotically gapped quantum spin chains
Suppose I have a sequence of gapped, spin-$1/2$, translationally invariant quantum spin chains $\{H_1, H_2,H_3\cdots\}$ with interactions of range $\leq 2$ (i.e. no further than nearest-neighbors).
...
- 985
4
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What is the relation between the Holstein-Primakoff Transformation and Bethe's Ansatz for the Heisenberg Ferromagnet?
Bethe's Ansatz is a method to find the eigenenergies and eigenstates of the Heisenberg ferromagnet (see also spin waves). For a general n-excitation state it involves solving rather complicated ...
- 11.6k
2
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How do phonons and spinwaves interact? [closed]
What governs the coupling of acoustic phonons to transverse and longitudinal spinwaves? Is there a simple picture?
- 117
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2
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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
1
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2
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218
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Why does a spinning nucleon generate a magnetic field?
I am trying to understand how NMR works, but I am not sure why a spinning nucleon produces a magnetic field. Is this a consequence of the quark structure inside?
- 3,997
2
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Can someone explain to me the Rokhsar-Kivelson Hamiltonian? [closed]
The following paper shows the hamiltonian of the 2D quantum dimer gas (page 2)
http://www-thphys.physics.ox.ac.uk/people/ClaudioCastelnovo/Talks/050209_MIT.pdf
Here are some questions I have.
Why ...
- 244
6
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3
answers
12k
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Nuclear Spin of Sodium 23
I am actually calculating the nuclear spin of Sodium 23. Here we have 11 protons and 12 neutrons. Now both the nuclei are short of the magic numbers. When I use the shell model for protons and ...
- 95
8
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2
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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
3
votes
1
answer
216
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How do we determine the statistics and spin of quasi-particles?
I am considering the Heisenberg XXZ model at the moment. In the literature it says that (in the $J\Delta\rightarrow\infty$ limit, i.e. the ferromagnetic Ising regime) one can either view low-energy ...
- 2,910
5
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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. ...
- 2,910
2
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Spin Transition Energies
I am reading a paper:
http://arxiv.org/ftp/arxiv/papers/1305/1305.2445.pdf
On p. 22, the following Hamiltonian is given:
$$ H = \mu_B g \mathbf{B} \cdot \mathbf{S} + D(S_Z^2+\frac{1}{3}S(S+1)) + E(...
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