伊辛模型MATLAB源代碼

1、伊辛(Ising)模型MATLAB源程序代碼clear all;close all;clcN=16;Te=0:0.2:5;imax=;MT=zeros(1,length(Te);Cv=zeros(1,length(Te);xx=zeros(1,length(Te);L=1;k=1;for T=TeMt=zeros(1,imax);step=;spin=round(rand(N).*2-1;subplot(3,2,1)gspin=pcolor(spin);colormap(gray(2);title(自旋分布情況);Mt=zeros(1,imax);subplot(3,2,2)gMt=plot(

2、1:imax,Mt);axis(0 imax -1.1 1.1);title(固定溫度下的磁矩);%xlabel(時間);%ylabel(Mt);%initial energy idx=repmat(:,ndims(spin),1); idx1=N 1:N-1; Etotal=spin(idx:); idx=repmat(:,ndims(spin),1); idx2=N 1:N-1; Etotal=Etotal+spin(idx:); idx=repmat(:,ndims(spin),1); idx1=2:N 1; Etotal=Etotal+spin(idx:); idx=repmat(:,

3、ndims(spin),1); idx2=2:N 1; Etotal=Etotal+spin(idx:); Etotal=spin.*Etotal; Et0=zeros(1,imax); Et0(1)=-sum(sum(Etotal)/2; subplot(3,2,3);gEt=plot(1:imax,Et0);Ett=Et0(1); title(固定溫度下的能量); %xlabel(時間); %ylabel(Et);%energy end subplot(3,2,4); gMT=plot(Te,MT,o-); axis(0 max(Te) 0 1.1); title(磁矩隨溫度T的變化);

4、%xlabel(T); %ylabel(MT); subplot(3,2,5) gCv=plot(Te,Cv,o-); %axis(0 max(Te) 0 700); title(熱容隨溫度T的變化); %xlabel(T); %ylabel(Cv); subplot(3,2,6) gxx=plot(Te,xx,o-); %axis(0 max(Te) 0 0.1); title(磁導率隨溫度T的變化); %xlabel=(T); %ylabel=(X);for i=2:imax a=ceil(rand(1,2).*N); if a(1)=1 xl=N; else xl=a(1)-1; end

5、 if a(1)=N xr=1; else xr=a(1)+1; end if a(2)=1 yd=N; else yd=a(2)-1; end if a(2)=N yu=1; else yu=a(2)+1; end ds=spin(a(1),yu)+spin(a(1),yd)+spin(xl,a(2)+spin(xr,a(2);de=2.*spin(a(1),a(2).*ds; if randexp(-de/T) spin(a(1),a(2)=-spin(a(1),a(2); Ett=Ett+de; end Mt(i)=sum(sum(spin)/(N2); Et0(i)=Ett; if mod(i,step)=0 set(gspin,Cdata,double(spin); set(gMt,Ydata,Mt); set(gEt,Ydata,Et0); drawnow end end Cv(L)=1/(T2).*(mean(Et0.2)-mean(Et0)2); xx(L)=1/T.*(mean(Mt.2)-mean(Mt)2); MT(L)=mean(abs(Mt(0.9*imax:imax); set(gMT,Ydata,