All Questions
24
questions
3
votes
1
answer
73
views
Ising Model magnetisation
I am simulating the 2D Ising Model and specifically looking at the time evolution of magnetisation $m$. Now, in the non-equilibrium state, magnetisation will grow as a power law with time $t$, if ...
1
vote
0
answers
93
views
Can the specific heat capacity in the Ising Model be negative?
Im working on a numerical method for the Ising model. I'm asked to calculate both the absolute magnetizetion and the specific heat capacity:
$$c = \frac{\beta^2}{N} \left( \langle H^2 \rangle - \...
1
vote
1
answer
121
views
Two-point-correlation in the 3D ising model
I am currently coding a 3D (Monte-Carlo) implementation of the Ising model, using the single spin-flip & Wolff algorithm.
So far, I was able to calculate all the interesting observables, like $M$ ...
2
votes
2
answers
128
views
Phase transition in Ising Model with local $\mathbb{Z}_2$ symmetry
I am studying the Ising model with a local $\mathbb{Z}_2$ gauge symmetry
\begin{equation}
\mathcal{H} = -\sum_{\text{plaquettes}} \sigma^z(\vec{x}, \vec{\mu})\sigma^z(\vec{x}+\vec{\mu}, \vec{\nu})\...
0
votes
0
answers
77
views
Question about Monte Carlo Simulation of 2D lattice Ising Model and Classical Heisenberg Model
I'm trying run and experiment with Monte Carlo Simulations of 2D lattice Ising Model and Classical Heisenberg Model.
I've made a brief research on both models and I saw that main differences of these ...
1
vote
0
answers
61
views
Difference between two Monte-Carlo methods in Ising model
I was working on a Monte-Carlo simulation of the Ising model. It seems that we have two different way to flip a single spin and I didn't quite understand the difference between them.
Say we have $N\...
1
vote
1
answer
277
views
Simulating the Ising Model, but with three states instead of two
Recall the homogeneous Ising energy of a configuration σ in the absence of a magnetic field is given by the Hamiltonian function
$$
H(\sigma) = -\sum_{\langle i~j\rangle} \sigma_i \sigma_j ,
$$
where ...
5
votes
0
answers
705
views
Decorrelation times for a 2D Ising Model over a range of temperatures
So, I'm trying to simulate the Ising Model on a 2D square lattice of spins. When exploring the auto correlation of the magnetisation:
Where the auto covariance: $$A(T) = \langle(M(t)\ - \langle M\...
3
votes
1
answer
128
views
Is there any point in doing Monte Carlo on classical 2D Ising spin systems? [closed]
The partition function of a classical Ising spin system with arbitrary bonds on any planar graph can be evaluated in polynomial time, through the FKT algorithm. And if I understand correctly, this ...
1
vote
1
answer
361
views
Generating Ising model steady state configurations
What is the most efficient way to simulate steady state configurations of the Ising model? I am just interested in having a large set of random steady state configurations of the 1D Ising model (with ...
0
votes
2
answers
505
views
Fluctuating magnetization curve in ising model
I am working on Metropolis-Montecarlo algorithm for 2D Ising model in python partly based on this document. I ran the simulation for 100 times on a 25 x 25 lattice with external magnetic field B = 0. ...
1
vote
0
answers
745
views
Using MATLAB to simulate the Ising Model [closed]
I am using MATLAB to simulate a 1D Ising Chain. I am running into an issue where when trying to find heat capacity, my system has a tremendous amount of noise. I'll post my code and an image of the ...
1
vote
1
answer
100
views
Why are the autocorrelations larger for the energy at the critical temperature?
Considering a simulation with the Swendsen-Wang algorithm for the 3-D cubic lattice I wanted to have a look at the auto-correlations, and expecting it to be quite small considering Swendsen-Wang is a ...
0
votes
0
answers
336
views
How to calculate the autocorrelation function of magnetic susceptibility for the Ising model?
In the paper Wolff U. 1989. Physics Letters B. 228(3):379–82, the autocorrelation time of susceptibility, $\tau_\chi$ was calculated, but the way to do so was not clearly explained in the paper.
To ...
0
votes
2
answers
138
views
Evaluating the quality of Monte Carlo simulations for 3D Ising model
Suppose I have developed a new Monte Carlo method, and I plan to test this method on studying the magnetization of a 3D Ising model at some non-zero temperature $T$. The coupling is nearest neighbor, ...