From c91fccd07c9ba1753d7006482512352423046c74 Mon Sep 17 00:00:00 2001 From: Ian Jauslin Date: Thu, 30 Mar 2017 02:47:52 +0000 Subject: As presented at Princeton University on 2017-03-30 --- figs/bands.fig/bands.py | 55 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) create mode 100644 figs/bands.fig/bands.py (limited to 'figs/bands.fig/bands.py') diff --git a/figs/bands.fig/bands.py b/figs/bands.fig/bands.py new file mode 100644 index 0000000..57d03b8 --- /dev/null +++ b/figs/bands.fig/bands.py @@ -0,0 +1,55 @@ +#!/usr/bin/env python + +## compute the bands for bilayer graphene (no g4 or delta) + +from math import * +import cmath +import numpy + +g1=0.1 +g3=0.33*g1 + +def Omega(x,y): + return(1+2*cmath.exp(-3j/2*x)*cos(sqrt(3)/2*y)) + +# Hamiltonian +def H(x,y): + return(numpy.array(\ + [[0,g1,0,Omega(x,y).conjugate()],\ + [g1,0,Omega(x,y),0],\ + [0,Omega(x,y).conjugate(),0,g3*Omega(x,y)*cmath.exp(3j*x)],\ + [Omega(x,y),0,g3*(Omega(x,y).conjugate())*cmath.exp(-3j*x),0]]\ + )) + +# eigenvalues +def eigsH(x,y): + return(numpy.linalg.eigvals(H(x,y))) + + +# resolution +nrpoints=55 +# xrange +xmin,xmax=0,4*pi/3 +# yrange +ymin,ymax=-2*pi/sqrt(3),2*pi/sqrt(3) + +# sample points +x=numpy.linspace(xmin,xmax,nrpoints) +y=numpy.linspace(ymin,ymax,nrpoints) +x,y=numpy.meshgrid(x,y) + +# data points +z=numpy.zeros((4,nrpoints,nrpoints)) +for i in range(0,nrpoints): + for j in range(0,nrpoints): + eigs=numpy.sort(numpy.real(eigsH(x[i,j],y[i,j]))) + for k in range(0,4): + z[k,i,j]=(eigs[k]) + +# output +for i in range(0,nrpoints): + for j in range(0,nrpoints): + for k in range(0,4): + print("%10f %10f %10f %d " % (x[i,j],y[i,j],z[k,i,j],k),end='') + print() + print() -- cgit v1.2.3-54-g00ecf