def measure1(siteindex):
if which=='RHO':
op=opunit_N(spaceconfig,index=None,siteindex=siteindex)
else:
raise NotImplementedError()
if isinstance(op,OpCollection):
m=sum([get_expect(opi,ket=ket) for opi in op.ops])
else:
m=get_expect(op,ket=ket)#,bra=ket.tobra(labels=ket.labels))
print 'Get %s for site %s = %s @RANK: %s'%(which,siteindex,m.item(),RANK)
return m
def measure1(siteindex):
if which=='SDW': #cj+ sx cj ~ (-1)^j*m
op=opunit_S(which='x',spaceconfig=spaceconfig,siteindex=siteindex)
elif which=='sPDW': #cjup+ cjdn+ ~ (-1)^j*G
cup_d=opunit_C(dag=True,index=0,spaceconfig=spaceconfig,siteindex=siteindex)
cdn_d=opunit_C(dag=True,index=1,spaceconfig=spaceconfig,siteindex=siteindex)
cup_0=opunit_C(dag=False,index=0,spaceconfig=spaceconfig,siteindex=anchor)
cdn_0=opunit_C(dag=False,index=1,spaceconfig=spaceconfig,siteindex=anchor)
op=(cup_0*cdn_0)*(cup_d*cdn_d)
if isinstance(op,OpString):
op.compactify()
elif which=='bSDW': #cj+ sx cj+1 + h.c. ~ (-1)^j*M
opi=get_bsdw_op(spaceconfig,siteindex,nsite=nsite)
op0=get_bsdw_op(spaceconfig,siteindex=anchor,nsite=nsite)
op=(op0*opi).compactify()
op.insert_Zs(spaceconfig)
elif which=='bSDW1':
op=get_bsdw_op2(spaceconfig,siteindex,nsite=nsite)
op.insert_Zs(spaceconfig)
elif which=='TX': #<S_z^2> - <S_z>^2
op_sz=opunit_S(which='z',spaceconfig=spaceconfig,siteindex=siteindex)
op=op_sz*op_sz
elif which=='CDW':
op_n=opunit_N(spaceconfig,index=None,siteindex=siteindex)
op_n0=opunit_N(spaceconfig,index=None,siteindex=anchor)
op=op_n*op_n0
elif which=='RHO':
op=opunit_N(spaceconfig,index=None,siteindex=siteindex)
elif which=='triplet': #cj+ sx isy (cj+1+)^t
cup_d=opunit_C(dag=True,index=0,spaceconfig=spaceconfig,siteindex=siteindex)
cup_dp=opunit_C(dag=True,index=0,spaceconfig=spaceconfig,siteindex=siteindex+1)
op=cup_d*cup_dp
#raise NotImplementedError()
elif which=='Sx':
op=opunit_S(which='x',spaceconfig=spaceconfig,siteindex=siteindex)
elif which=='SxSx0':
op_Sx=opunit_S(which='x',spaceconfig=spaceconfig,siteindex=siteindex)
op_Sx=opunit_S(which='x',spaceconfig=spaceconfig,siteindex=anchor)
op=op_Sx*op_Sx
elif which=='DBL':
op_n=opunit_N(spaceconfig,index=0,siteindex=siteindex)*opunit_N(spaceconfig,index=1,siteindex=siteindex)
op_n0=opunit_N(spaceconfig,index=0,siteindex=nsite/2)*opunit_N(spaceconfig,index=1,siteindex=anchor)
op=op_n*op_n0
else:
raise NotImplementedError()
if isinstance(op,OpCollection):
m=sum([get_expect(opi,ket=ket) for opi in op.ops])
else:
m=get_expect(op,ket=ket)#,bra=ket.tobra(labels=ket.labels))
print 'Get %s for site %s = %s @RANK: %s'%(which,siteindex,m,RANK)
return m
def measure_charge(K1,K2,U,nsite,usemps=True):
'''
measure the particle number for 6 sites.
'''
model,expander=get_solving_system(K1,K2,U=U,nsite=nsite,mu=0.,t=1.,evolutor_type='null',periodic=False)
E,V=solve_direct(model,k=1)
if usemps:
ns=[opunit_N(spaceconfig=expander.spaceconfig,siteindex=i) for i in xrange(nsite)]
mps=state2MPS(V[:,0],sitedim=expander.spaceconfig.hndim,l=0)
dos=[expect_onsite(ket=mps,opunit=ns[i]) for i in xrange(nsite)]
else:
spaceconfig=model.hgen.spaceconfig
vec=V[:,0]
ns=[op_simple_onsite(spaceconfig=spaceconfig,label='n%s'%i,index=spaceconfig.c2ind(array([[0,i,0],[1,i,0]]))) for i in xrange(nsite)]
dos=[vec.conj().dot(ns[i]().dot(vec)) for i in xrange(nsite)]
ion()
plot(dos)
ylim(0,2)
pdb.set_trace()
def dos4mps(spaceconfig,ket):
'''
Get dos from ground states.
Parameters:
:spaceconfig: <SuperSpaceConfig>, the configuration of Hilbert space.
:ket: <MPS>, the state.
Return:
tuple of (nup, ndn), the dos for up and down spin.
'''
nl=[[],[]]
for i in xrange(ket.nsite):
bra=ket.tobra(labels=[ket.labels[0],ket.labels[1]+"'"])
for spin in xrange(2):
ni=opunit_N(spaceconfig,index=spin,siteindex=i)
#nn=get_expect(ni,ket=ket,bra=None)
nn=expect_onsite(ni,ket=ket,bra=None)
nl[spin].append(nn)
print 'measure %s-th site -> %s.'%(i,nn)
return array(nl)
def chmu(dmrgegn,dmu):
'''Reset the hamiltonian.'''
nsite=dmrgegn.hgen.nsite
isweep,pos,direction=dmrgegn.status['isweep'],dmrgegn.status['pos'],dmrgegn.status['direction']
if isweep>1 or direction!='->' or pos!=1: return
MAG=0.1
hgen=dmrgegn.hgen
hchain=hgen.hchain
dmu_opc=0
if dmu!=0 and isweep==0 and pos==1 and direction=='->':
if dmu>0: MAG=-MAG
for i in xrange(nsite):
ouN=opunit_N(spaceconfig=hgen.spaceconfig,siteindex=i)
opi=MAG*(-1)**i*ouN
if isinstance(opi,OpUnit):
opi.siteindex=i
dmu_opc=dmu_opc+opi
opcl=copy.deepcopy(hchain)
opcl.insert_Zs(spaceconfig=hgen.spaceconfig)
if not dmrgegn.reflect:
opcr=copy.deepcopy(hchain)
opcr=site_image(opcr,NL=0,NR=hgen.nsite,care_sign=True)
opcr.insert_Zs(spaceconfig=hgen.spaceconfig)
#add twisting parameters.
if isweep==0 and pos==1 and direction=='->':
if dmu_opc is not 0:
opcr=opcr-dmu_opc
opcl=opcl+dmu_opc
for hgen in dmrgegn.LPART.values():
hgen.evolutees['H'].opc=opcl
if not dmrgegn.reflect:
for hgen in dmrgegn.RPART.values():
hgen.evolutees['H'].opc=opcr
elif isweep==1 and pos==1 and direction=='->':
for hgen in dmrgegn.LPART.values():
hgen.evolutees['H'].opc=opcl
if not dmrgegn.reflect:
for hgen in dmrgegn.RPART.values():
hgen.evolutees['H'].opc=opcr
