Questions tagged [spin-glass]

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Textbooks about spin-glasses for beginners

I am a Ph.D. student in Physics attending my second year. I would like to ask you whether you know any good textbook about spin-glasses (and physics of complex systems in general) for beginners. ...
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What is the intuition behind the statement that non-equilibrium systems with static disorder are self-averaging?

In this paper(1) by C. De Dominics, he makes the argument that in a dynamical statistical mechanics system, one doesn't need to apply the replica trick and can directly disorder average the generating ...
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$p$-spin spherical spin glass

Consider the $p$-spin spherical spin glass model with Hamiltonian $$H_{N,p}(\sigma)=\frac{1}{{N}^{\frac{(p-1)}{2}}} \sum \limits_{i_1,...i_p} J_{i_1,...i_p} \sigma_{i_1} \sigma_{i_2} .. \sigma_{i_p} $$...
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Spin glasses overlap

Suppose you have a spin glass simulation in which the standard Metropolis MC algorithm is used to sample phase space. The we calculate the equivalent for the lattice system of the self intermediate ...
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1answer
167 views

Flipping more than one spin in Metropolis Monte Carlo algorithms

In lattice systems such as Ising model or spin glasses, the standard Monte Carlo simulation with Metropolis algorithm works by proposig a single spin flip and then accepting or rejecting the proposal ...
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Why do we disorder-average before/after taking the logarithm of the partition function for annealed/quenched disorder?

Pg. 19 of these notes says Crucially, the [disorder] average $\overline{\log Z}$ has to be computed after taking the logarithm. Such an average is called quenched ... Computing the average first, ...
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Numerical solution of Parisi equations for the SK spin-glass model

I am trying to reproduce the numerical solution of the so-called Parisi equations for the Sherrington-Kirkpatrick (SK) model. There are at least two main methods to solve these equations, and ...
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1answer
320 views

Why is the critical exponent $\alpha$ negative at the Ising spin-glass transition?

The specific heat usually diverges at a phase transition - typically as a power-law, giving a critical exponent $\alpha > 0$. (Although in 2D, sometimes the divergence is only logarithmic, as with ...
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54 views

Antiferromagnetic-like interaction, but preferring 120/240 angles instead of 180?

Antiferromagnetic interaction energetically prefers opposite spins for neighbors: rotated by 180 degrees. But imagine there is $S_3$ symmetry: 3 possibilities rotated by 120 degrees and ...
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1answer
86 views

Spin-glass and spin-fluid phase

I was wondering what is the difference between a spin-fluid Heisenberg Magnet and spin-glass Heisenberg Magnet. As far as I understand in a spin-glass the spins are randomly oriented compared to a ...
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1answer
35 views

EA order parameter $q(T)$ does not have limits paper says it has

This is related to the paper "Theory of Spin Glasses" by Edwards and Anderson (EA). It can be found at http://iopscience.iop.org/article/10.1088/0305-4608/5/5/017/pdf for those who may want to read ...
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Is there an entropy crisis in Spin Glasses?

If you cool a material and avoid crystallization, you get a supercooled liquid and ultimately a glass. If you extrapolate the entropy of the supercooled liquid, at some point it intersects with the ...
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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 ...
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272 views

Statistical specific heat as energy fluctuation in spin glasses

Consider the specific heat (in statistical sense, as energy fluctuation in the canonical ensemble) of a complex model, something similar to a spin glass. Is the specific heat defined on fluctuations ...
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What is the Superpartner of a glass? [closed]

A little context: This summer I visited Switzerland and had the chance to tour CERN. While there, I saw through an open door this question written at the top of a chalkboard in John Ellis's office. I ...
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446 views

How does the spinglass algorithm work when used for community detection in networks?

I am reading the article "Statistical Mechanics of Community Detection" by Jörg Reichardt and Stefarn Bornholdt, which describes how to use the spinglass model from physics to determine communities in ...
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1answer
112 views

Do Monte-Carlo updates carry a physical significance in statistical mechanics?

A common example to introduce Monte-Carlo methods in statistical mechanics is to work out the properties of the 2D square lattice Ising model and compare the obtained results with Onsager's exact ...
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The “replica trick” initial formula?

In Spin-glass theory for pedestrians by Castellani and Cavagna, the initial formula used to introduce the replica trick is written as: $$\overline{\log Z}=\lim_{n\rightarrow0}\frac{1}{n}\log\overline{...
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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. ...
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2k views

What is the difference between spin glass and spin liquid?

What is the difference between spin glass and spin liquid? Do they both originate from frustration?
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484 views

Does the spin glass corresponding to a restricted Boltzmann machine have a characteristic timescale?

From what I gather, a Boltzmann machine can be identified with a spin glass. Though I don't know the details yet (and would welcome any references within the last 5 years--not, e.g. MacKay, etc.), I ...