def get_mps(K,Jp,J1=1.,J2=0.2412,nsite=30,which='finite',data_file=None):
'''
Run finite-DMFT/lanczos for two impurity Kondo model to get the Ground state energy.
Parameters:
:J1/J2/K/Jp: float, the parameters defining the model.
:nsite: integer, the number of sites, must be even.
:which: 'finite'/'lanczos', select the method to solve the chain, 'finite dmrg' or 'lanczos'.
'''
assert(which=='finite' or which=='lanczos')
assert(nsite%2==0)
model=TIKM(J1=J1,J2=J2,K=K,Jp=Jp,nsite=nsite)
hgen=SpinHGen(spaceconfig=model.spaceconfig,evolutor=MaskedEvolutor(hndim=model.spaceconfig.hndim) if which=='finite' else NullEvolutor(hndim=2))
dmrgegn=DMRGEngine(hchain=model.H_serial,hgen=hgen,tol=0)
if which=='lanczos':
H=get_H(H=model.H_serial,hgen=hgen)
EG,EV=eigsh(H,k=1)
mps=state2MPS(EV[:,0])
else:
EG=dmrgegn.run_finite(endpoint=(2,'<-',0),maxN=[10,20],tol=0)[-1]
mps=dmrgegn.get_mps(direction='<-') #right normalized initial state
if data_file is not None:
mps.save(data_file)
return mps
def test_dmrg_infinite(self):
'''test for infinite dmrg.'''
maxiter=100
model=self.get_model(maxiter+2,1)
hgen=SpinHGen(spaceconfig=SpinSpaceConfig([2,1]),evolutor=MaskedEvolutor(hndim=2))
dmrgegn=DMRGEngine(hchain=model.H_serial,hgen=hgen,tol=0)
EG=dmrgegn.run_infinite(maxiter=maxiter,maxN=20,tol=0)[-1]
assert_almost_equal(EG,0.25-log(2),decimal=2)
def dmrgrun(self,model):
'''Get the result from DMRG'''
#run dmrg to get the initial guess.
hgen=ExpandGenerator(spaceconfig=model.spaceconfig,H=model.H_serial,evolutor_type='masked')
dmrgegn=DMRGEngine(hgen=hgen,tol=0,reflect=True)
dmrgegn.use_U1_symmetry('M',target_block=zeros(1))
EG,mps=dmrgegn.run_finite(endpoint=(5,'<-',0),maxN=30,tol=1e-12)
return EG,mps
def test_dmrg_infinite(self):
'''test for infinite dmrg.'''
maxiter=100
model=self.get_model(maxiter+2,1)
hgen=RGHGen(spaceconfig=SpinSpaceConfig([2,1]),H=model.H_serial,evolutor_type='masked')
dmrgegn=DMRGEngine(hgen=hgen,tol=0,reflect=True)
dmrgegn.use_U1_symmetry('M',target_block=0)
EG=dmrgegn.run_infinite(maxiter=maxiter,maxN=20,tol=0)[0]
assert_almost_equal(EG,0.25-log(2),decimal=2)
def test_dmrg_infinite(self):
'''test for infinite dmrg.'''
maxiter = 100
model = self.get_model(maxiter + 2, 1)
hgen = ExpandGenerator(spaceconfig=SpinSpaceConfig([1, 2]),
H=model.H_serial,
evolutor_type='masked')
dmrgegn = DMRGEngine(hgen=hgen, tol=0, reflect=True, iprint=10)
dmrgegn.use_U1_symmetry('M', target_block=zeros(1))
EG = dmrgegn.run_infinite(maxiter=maxiter, maxN=20, tol=0)[0]
assert_almost_equal(EG, 0.25 - log(2), decimal=2)
def test_dmrg_finite(self):
'''
Run iDMFT for heisenberg model.
'''
model=self.get_model(10,1)
hgen1=SpinHGen(spaceconfig=SpinSpaceConfig([2,1]),evolutor=NullEvolutor(hndim=2))
hgen2=SpinHGen(spaceconfig=SpinSpaceConfig([2,1]),evolutor=MaskedEvolutor(hndim=2))
dmrgegn=DMRGEngine(hchain=model.H_serial,hgen=hgen1,tol=0)
EG1=dmrgegn.direct_solve()
dmrgegn=DMRGEngine(hchain=model.H_serial,hgen=hgen2,tol=0)
EG2=dmrgegn.run_finite(endpoint=(5,'<-',0),maxN=[10,20,30,40,40],tol=0)[-1]
assert_almost_equal(EG1,EG2,decimal=4)
def test_dmrg_finite(self):
'''
Run iDMFT for heisenberg model.
'''
nsite=10
model=self.get_model(nsite,1)
hgen1=RGHGen(spaceconfig=SpinSpaceConfig([2,1]),H=model.H_serial,evolutor_type='null')
hgen2=RGHGen(spaceconfig=SpinSpaceConfig([2,1]),H=model.H_serial,evolutor_type='masked')
H=get_H(hgen1)
EG1=eigsh(H,k=1,which='SA')[0]
dmrgegn=DMRGEngine(hgen=hgen2,tol=0,reflect=True)
dmrgegn.use_U1_symmetry('M',target_block=0)
EG2=dmrgegn.run_finite(endpoint=(5,'<-',0),maxN=[10,20,30,40,40],tol=0)[0]
assert_almost_equal(EG1,EG2,decimal=4)
def test_vmps(self):
'''
Run vMPS for Heisenberg model.
'''
nsite=10
filename='mps_heisenberg_%s.dat'%(nsite)
model=self.get_model(nsite,which=1)
#mps=MPS.load(filename)
#run dmrg to get the initial guess.
hgen=RGHGen(spaceconfig=SpinSpaceConfig([2,1]),H=model.H_serial,evolutor_type='masked')
dmrgegn=DMRGEngine(hgen=hgen,tol=0,reflect=True)
dmrgegn.use_U1_symmetry('M',target_block=0)
EG,mps=dmrgegn.run_finite(endpoint=(1,'<-',0),maxN=40,tol=1e-12)
mps.save(filename)
#run vmps
vegn=VMPSEngine(H=model.H,k0=mps)
vegn.run()
def test_vmps(self):
'''
Run vMPS for Heisenberg model.
'''
nsite=10
filename='mps_heisenberg_%s.dat'%(nsite)
model=self.get_model(nsite,which=1)
#mps=MPS.load(filename)
#run dmrg to get the initial guess.
hgen=SpinHGen(spaceconfig=SpinSpaceConfig([2,1]),evolutor=MaskedEvolutor(hndim=2))
dmrgegn=DMRGEngine(hchain=model.H_serial,hgen=hgen,tol=0)
dmrgegn.run_finite(endpoint=(1,'<-',0),maxN=40,tol=1e-12)
#hgen=dmrgegn.query('r',nsite-1)
mps=dmrgegn.get_mps() #right normalized initial state
mps.save(filename)
#run vmps
vegn=VMPSEngine(H=model.H,k0=mps)
vegn.run()
def spin1_vmps(J, Jz, h, nsite, append=False):
"""
Run vMPS for Heisenberg model.
"""
filename = "mps_heisenberg_%s.dat" % (nsite)
model = Spin1Model(J=J, Jz=Jz, h=h, nsite=nsite)
if append:
mps = MPS.load(filename)
else:
# run dmrg to get the initial guess.
hgen = RGHGen(spaceconfig=SpinSpaceConfig([2, 1]), H=model.H_serial, evolutor_type="masked")
dmrgegn = DMRGEngine(hgen=hgen, tol=0)
EG = dmrgegn.run_finite(endpoint=(1, "<-", 0), maxN=10, tol=0)[-1]
# hgen=dmrgegn.query('r',nsite-1)
mps = dmrgegn.get_mps(direction="<-") # right normalized initial state
mps.save(filename)
# run vmps
vegn = VMPSEngine(H=model.H, k0=mps)
vegn.run()
def test_dmrg_finite(self):
'''
Run iDMFT for heisenberg model.
'''
nsite = 10
model = self.get_model(nsite, 1)
hgen1 = ExpandGenerator(spaceconfig=SpinSpaceConfig([1, 2]),
H=model.H_serial,
evolutor_type='null')
hgen2 = ExpandGenerator(spaceconfig=SpinSpaceConfig([1, 2]),
H=model.H_serial,
evolutor_type='masked')
H = get_H(hgen1)
EG1 = eigsh(H, k=1, which='SA')[0]
dmrgegn = DMRGEngine(hgen=hgen2, tol=0, reflect=True)
dmrgegn.use_U1_symmetry('M', target_block=zeros(1))
EG2 = dmrgegn.run_finite(endpoint=(5, '<-', 0),
maxN=[10, 20, 40, 40, 40],
tol=0)[0]
assert_almost_equal(EG1, EG2, decimal=4)
def heisenberg_vmps(J,Jz,h,nsite,append=False):
'''
Run vMPS for Heisenberg model.
'''
filename='mps_heisenberg_%s.dat'%(nsite)
model=HeisenbergModel(J=J,Jz=Jz,h=h,nsite=nsite)
if append:
mps=MPS.load(filename)
else:
#run dmrg to get the initial guess.
hgen=RGHGen(spaceconfig=model.spaceconfig,H=model.H_serial,evolutor_type='masked')
dmrgegn=DMRGEngine(hgen=hgen,tol=0)
EG=dmrgegn.run_finite(endpoint=(1,'<-',0),maxN=10,tol=0)[-1]
#hgen=dmrgegn.query('r',nsite-1)
mps=dmrgegn.get_mps(direction='<-') #right normalized initial state
mps.save(filename)
#run vmps
vegn=VMPSEngine(H=model.H,k0=mps)
vegn.run()
def spin1_dmrg(J, Jz, h, nsite=10, which="finite", J2=0, J2z=None):
"""
Run iDMFT for heisenberg model.
"""
if J2 == 0:
model = Spin1Model(J=J, Jz=Jz, h=h, nsite=nsite)
else:
model = Spin1Model(J=J, Jz=Jz, J2=J2, J2z=J2z, h=h, nsite=nsite)
hgen = RGHGen(spaceconfig=SpinSpaceConfig([2, 1]), H=model.H_serial, evolutor_type="masked")
dmrgegn = DMRGEngine(hgen=hgen, tol=0, reflect=True)
dmrgegn.use_U1_symmetry("M", target_block=0)
if which == "infinite":
dmrgegn.run_infinite(maxiter=50, maxN=20, tol=0)
elif which == "lanczos":
dmrgegn.direct_solve()
else:
dmrgegn.run_finite(endpoint=(5, "<-", 0), maxN=[10, 20, 30, 40, 40], tol=0)
pdb.set_trace()
def test_lanczos(self):
'''test for directly construct and solve the ground state energy.'''
model = self.get_model(10, 1)
hgen1 = ExpandGenerator(spaceconfig=SpinSpaceConfig([1, 2]),
H=model.H_serial,
evolutor_type='null')
hgen2 = ExpandGenerator(spaceconfig=SpinSpaceConfig([1, 2]),
H=model.H_serial,
evolutor_type='normal')
dmrgegn = DMRGEngine(hgen=hgen1, tol=0, iprint=10)
H = get_H(hgen=hgen1)
H2, bm2 = get_H_bm(hgen=hgen2, bstr='M')
Emin = eigsh(H, k=1)[0]
Emin2 = eigsh(bm2.extract_block(H2, (zeros(1), zeros(1)),
uselabel=True),
k=1)[0]
print 'The Ground State Energy is %s, tolerence %s.' % (Emin,
Emin - Emin2)
assert_almost_equal(Emin, Emin2)
def solve1(J,Jz,h,target_block,nsite=10,parity=None,nspin=2):
'''
Run iDMFT for heisenberg model.
'''
model=HeisenbergModel(J=J,Jz=Jz,h=h,nsite=nsite,nspin=nspin)
suffix='%s_%s%s.dat'%(model.get_str(),target_block,parity)
filename_mps='data/mps_'+suffix
filename_eng='data/eng_'+suffix
parity=None
hgen=RGHGen(spaceconfig=model.spaceconfig,H=model.H_serial,evolutor_type='masked')
dmrgegn=DMRGEngine(hgen=hgen,tol=0,reflect=parity is not None,eigen_solver='JD')
dmrgegn.use_U1_symmetry('M',target_block=target_block)
if parity is not None:
dmrgegn.use_disc_symmetry({'C':parity})
t0=time.time()
Emin,mps=dmrgegn.run_finite(endpoint=(5,'<-',0),maxN=[10,20,40,80,80],tol=1e-8)
t1=time.time()
print 'The Ground State Energy for %s: %s, Elapse %s.'%(model,Emin,t1-t0)
print 'FIN - CORE:%s'%RANK
mps.save(filename_mps)
savetxt(filename_eng,Emin)
return Emin,mps
def test_fsfermi(): dmrg=DMRGEngine(fslhgen,fsrhgen) dmrg.finite(mwarmup=10,mlist=[10,20,30,40,40])
def test_isfermi(): dmrg=DMRGEngine(fslhgen,fsrhgen) dmrg.infinite(m=40)
def test_ifermi(): dmrg=DMRGEngine(flhgen,frhgen) dmrg.infinite(m=40)
def test_fspin(): dmrg=DMRGEngine(lhgen,rhgen) dmrg.finite(mwarmup=10,mlist=[10,20,30,40,40])
def test_ispin(): dmrg=DMRGEngine(lhgen,rhgen) dmrg.infinite(m=20)
def test_tomps(): dmrg=DMRGEngine(lhgen,rhgen) dmrg.finite(mwarmup=10,mlist=[10]) dmps=dmrg.tomps() return dmps
