def show_mf(Vz,Delta,mu=0.,**kwargs):
LABELSIZE=14
model=RashbaModel(Vz=Vz,Delta=Delta,mu=mu,**kwargs)
filename_mf='data/mf_%s.npy'%model.get_str()
mfs=load(filename_mf); mfs=mfs*mfs.conj()
mfs=mfs.reshape([-1,4,mfs.shape[-1]])
sites=arange(1,mfs.shape[0]+1)
ion()
fig=figure(figsize=(7,5))
subplot(121)
plot(sites,mfs[...,0])
xlim(0,100)
ylim(-0.4,0.4)
xlabel('Site',fontsize=LABELSIZE)
ylabel('Amplitude',fontsize=LABELSIZE)
subplot(122)
plot(sites,mfs[...,1])
xlim(900,1000)
xlabel('Site',fontsize=LABELSIZE)
yticks([])
ylim(-0.4,0.4)
legend([r'$e\uparrow$',r'$e\downarrow$',r'$h\uparrow$',r'$h\downarrow$'],loc=2)
tight_layout()
pdb.set_trace()
savefig('data/mf_%s.png'%model.get_str())
def cal_dos_mf(Vz,Delta,mu=0.,**kwargs):
'''
show the meanfield band.
'''
model=RashbaModel(Vz=Vz,Delta=Delta,mu=mu,**kwargs)
filename_dos='data/dos_%s.dat'%model.get_str()
filename_mj='data/mf_%s.npy'%model.get_str()
hgen=model.hgen
if kwargs.get('kspace'):
kl=hgen.kspace.kmesh
hmesh=hgen.gethkmesh(kl)
else:
hmesh=hgen.H(dense=True)
#tridmat=sr2trid(hmesh)
#g=tinv(tridmat)
hmesh=Hmesh(hmesh)
emesh,vmesh=hmesh.getemesh(evalvk=True)
wlist=linspace(-3,3,501)
wlist,dos=Emesh(emesh).show_dos(wlist,geta=3e-3)
dosdata=concatenate([wlist[:,newaxis],dos[:,newaxis]],axis=1)
savetxt(filename_dos,dosdata)
if not kwargs.get('kspace'):
gate=0.01
has_mf=Vz>Delta and abs(mu)<sqrt(Vz**2-Delta**2)
print 'Has Majorana fermion: %s.'%has_mf
mjmask=abs(emesh)<gate
print 'Zero Energy States(abs(E) < %s) -> %s'%(gate,emesh[mjmask])
mjdata=vmesh[:,mjmask]
save(filename_mj,mjdata)
def plot_band(alpha,Vz,Delta,t=1.,mu=0.,nsite=100):
'''
show the meanfield band.
'''
model=RashbaModel(U=0.,alpha=alpha,Vz=Vz,Delta=Delta,t=t,mu=mu,nsite=nsite,periodic=True,kspace=True)
hgen=model.hgen
kl=hgen.kspace.kmesh-pi
hkmesh=hgen.gethkmesh(kl)
hmesh=Hmesh(hkmesh)
print hmesh.check_hermicity()
ekmesh=hmesh.getemesh()
LABELSIZE=14
ion()
fig=figure(figsize=(7,5))
plot(kl[:,0],ekmesh)
if True:#hgen.spaceconfig.nnambu==1:
axhline(y=0,ls='--',color='k')
text(1.8,-0.1,'$\mu=0$',ha='center',va='center',fontsize=14)
if Vz==0 and alpha!=0:
dy=alpha**2/2
annotate('',xy=(-alpha,-2*dy),xycoords='data',xytext=(alpha,-2*dy),\
arrowprops=dict(arrowstyle='<->',shrinkA=0,shrinkB=0))
plot([-alpha,-alpha],[-dy-0.1,-dy+0.1],color='k',ls='-')
plot([alpha,alpha],[-dy-0.1,-dy+0.1],color='k',ls='-')
text(0,-2*dy-0.1,r'$2\alpha$',va='center',ha='center',fontsize=14)
xlabel(r'$k$',fontsize=LABELSIZE)
ylabel('Energy($t$)')
xlim(-pi,pi)
xticks([-pi,0,pi],[r'$-\pi/a$','0',r'$-\pi/a$'],fontsize=14)
tight_layout()
pdb.set_trace()
savefig('data/band_%s.png'%model.get_str())
def show_dos(Vz,Delta,mu=0.,**kwargs):
LABELSIZE=14
model=RashbaModel(Vz=Vz,Delta=Delta,mu=mu,**kwargs)
filename_dos='data/dos_%s.dat'%model.get_str()
data=loadtxt(filename_dos)
wlist,dos=data[:,0],data[:,1]
ion()
fig=figure(figsize=(7,5))
plot(wlist,dos)
xlabel('$\omega$',fontsize=LABELSIZE)
ylabel('Density of States',fontsize=LABELSIZE)
axes([0.65,0.65,0.2,0.2])
xlim(-0.2,0.2)
xticks([-0.2,0,0.2])
ylim(0,0.5)
plot(wlist,dos)
pdb.set_trace()
savefig('data/dos_%s.png'%model.get_str())
def cal_G(Vz,Delta,mu=0.,siteindex=0,force=False,**kwargs):
'''
show the meanfield band.
'''
N=2001
model=RashbaModel(Vz=Vz,Delta=Delta,mu=mu,kspace=False,**kwargs)
hgen=model.hgen
filename='data/G00_%s.dat'%(model.get_str())
hndim=hgen.spaceconfig.nnambu*hgen.spaceconfig.nspin
wlist=linspace(-3,3,N)
t0=time.time()
if force:
hmesh=hgen.H(dense=True)
E,U=eigh(hmesh)
U0=U[:hndim]
else:
hmesh=hgen.H(dense=False).tobsr((hndim,hndim))
invG=sr2trid(-hmesh,p=None)
dg=invG.diagonal
I=identity(hndim)
gl=empty([N,4,4],dtype='complex128')
#gl=zeros([0,4,4],dtype='complex128')
geta=0.2e-3
for i,w in enumerate(wlist):
z=w+geta*1j
if force:
G00=(U0/(z-E)).dot(U0.T.conj())
else:
invG.diagonal=z*I+dg
G=get_inv_system(invG)
G00=G[0,0]
#gl.append(array(G00))
#gl=concatenate([gl,G00[newaxis]],axis=0)
gl[i]=G00
t1=time.time()
pdb.set_trace()
print 'Elapse -> %s'%(t1-t0)
al=-1./pi*gl.diagonal(axis1=-1,axis2=-2).imag
data=concatenate([wlist[:,newaxis],al],axis=1)
savetxt(filename,data)
def show_mr(Vz,Delta,mu=0.,indexer=0,**kwargs):
LABELSIZE=14
model=RashbaModel(Vz=Vz,Delta=Delta,mu=mu,**kwargs)
filename_mf='data/mf_%s.npy'%model.get_str()
mfs=load(filename_mf)
mfs=mfs.reshape([-1,4,mfs.shape[-1]])
sites=arange(1,mfs.shape[0]+1)
#sites=roll(sites,model.nsite/4,axis=0)
mfs=roll(mfs,model.nsite/4,axis=0)
ion()
fig=figure(figsize=(7,5))
plot(sites,mfs[...,indexer])
ylim(-0.2,0.2)
xlabel('Site',fontsize=LABELSIZE)
ylabel('Amplitude',fontsize=LABELSIZE)
legend([r'$e\uparrow$',r'$e\downarrow$',r'$h\uparrow$',r'$h\downarrow$'],loc=1)
text(model.nsite/2,0.05,'$\Delta=0.1,\mu=0.3$',ha='center')
text(model.nsite/8,0.05,'$\Delta=0,\mu=0$',ha='center')
tight_layout()
pdb.set_trace()
savefig('data/mf_%s%s.png'%(model.get_str(),indexer))