def __init__(self,t,lamb,mu,N=(100,100)):
self.t=t
self.lamb=lamb
self.mu=mu
spaceconfig=SpaceConfig([1,2,1,1],kspace=True)
hgen=KHGenerator(spaceconfig,propergauge=False)
#define the operator of the system
hgen.register_params({
't1':self.t,
'-mu':-self.mu,
'-ilamb':-1j*self.lamb,
})
#define a structure and initialize bonds.
rlattice=Square_Lattice(N=N,catoms=[zeros(2)])
hgen.uselattice(rlattice)
b1s=rlattice.cbonds[1] #the nearest neighbor
b0s=rlattice.cbonds[0] #the onsite term.
#add the hopping term.
op_t1=op_from_mats(label='hop1',spaceconfig=spaceconfig,mats=[sz]*len(b1s),bonds=b1s)
hgen.register_operator(op_t1,param='t1')
op_mu=op_from_mats(label='n',spaceconfig=spaceconfig,mats=[sz])
hgen.register_operator(op_mu,param='-mu')
bondx=b1s.query(bondv=array([1,0]))
_bondx=b1s.query(bondv=-array([1,0]))
bondy=b1s.query(bondv=array([0,1]))
_bondy=b1s.query(bondv=-array([0,1]))
op_l=op_from_mats(label='lamb',spaceconfig=spaceconfig,mats=[sx,-sx,sy,-sy],bonds=[bondx[0],_bondx[0],bondy[0],_bondy[0]])
hgen.register_operator(op_l,param='-ilamb')
self.hgen=hgen
def __init__(self,t,mu,M,N,periodic=False,usekspace=False):
if usekspace and not periodic:
raise ValueError('Don\'t be silly, how can you use kspace with non-periodic system!')
self.t,self.mu,self.M=t,mu,M
self.N=N
self.periodic=periodic
if usekspace:
spaceconfig=SpaceConfig([1,2,2,1],kspace=True)
hgen=KHGenerator(spaceconfig=spaceconfig,propergauge=False)
else:
spaceconfig=SpaceConfig(chorder([1,2,2*self.N,1]),kspace=False)
hgen=RHGenerator(spaceconfig=spaceconfig)
#define the operator of the system
hgen.register_params({
'-t':-self.t,
'M':self.M,
'-mu':-self.mu,
})
#define a structure and initialize bonds.
rlattice=Chain(N=N,catoms=[array([0.]),array([0.8])],a=array([2.]))
if periodic:
rlattice.usegroup(TranslationGroup(rlattice.N[:,newaxis]*rlattice.a,per=ones(1,dtype='bool')))
hgen.uselattice(rlattice)
b1s=rlattice.cbonds[1] if usekspace else rlattice.getbonds(1) #the nearest neighbor
b2s=rlattice.cbonds[2] if usekspace else rlattice.getbonds(2) #the nearest neighbor
#add the hopping term.
op_t1=op_simple_hopping(label='hop1',spaceconfig=spaceconfig,bonds=b1s+b2s)
hgen.register_operator(op_t1,param='-t')
op_n=op_simple_onsite(label='n',spaceconfig=spaceconfig)
hgen.register_operator(op_n,param='-mu')
#add the interaction term
I2=identity(2)
op_M_even=op_on_bond(label='Sx',spaceconfig=spaceconfig,mats=[sx]*len(b1s),bonds=b1s)
op_M_odd=op_on_bond(label='-Sx',spaceconfig=spaceconfig,mats=[-sx]*len(b2s),bonds=b2s)
hgen.register_operator(op_M_even,param='M')
hgen.register_operator(op_M_odd,param='M')
self.hgen=hgen