def get_Ising(self, h, J=1.): '''Get the hamiltonian.''' #the hamiltonian for Ising model Sz = opunit_Sz(spaceconfig=SpinSpaceConfig([1, 2])) Sx = opunit_Sx(spaceconfig=SpinSpaceConfig([1, 2])) H = -J * Sz.as_site(0) * Sz.as_site(1) + h * Sx.as_site(0) return H
def __init__(self, J, Jz, h, nsite, J2=0, J2z=None): self.spaceconfig = SpinSpaceConfig([1, 2]) I = OpUnitI(hndim=2) scfg = SpinSpaceConfig([1, 2]) Sx = opunit_Sx(spaceconfig=scfg) Sy = opunit_Sy(spaceconfig=scfg) Sz = opunit_Sz(spaceconfig=scfg) #with second nearest hopping terms. if J2 == 0: self.H_serial2 = None return elif J2z == None: J2z = J2 SL = [] for i in xrange(nsite): Sxi, Syi, Szi = copy.copy(Sx), copy.copy(Sy), copy.copy(Sz) Sxi.siteindex = i Syi.siteindex = i Szi.siteindex = i SL.append(array([Sxi, Syi, sqrt(J2z / J2) * Szi])) ops = [] for i in xrange(nsite - 1): ops.append(J * SL[i].dot(SL[i + 1])) if i < nsite - 2 and J2z != 0: ops.append(J2 * SL[i].dot(SL[i + 2])) mpc = sum(ops) self.H_serial = mpc
def get_Haldane(self, D, J=1.): '''Get the hamiltonian.''' #the hamiltonian for Ising model Sx = opunit_Sx(spaceconfig=SpinSpaceConfig([1, 3])) Sy = opunit_Sy(spaceconfig=SpinSpaceConfig([1, 3])) Sz = opunit_Sz(spaceconfig=SpinSpaceConfig([1, 3])) H = J * ( Sz.as_site(0) * Sz.as_site(1) + Sx.as_site(0) * Sx.as_site(1) + Sy.as_site(0) * Sy.as_site(1)) + D * Sz.as_site(0) * Sz.as_site(0) return H
def __init__(self, J, Jz, h, nsite): self.spaceconfig = SpinSpaceConfig([1, 2]) I = OpUnitI(hndim=2) scfg = SpinSpaceConfig([1, 2]) Sz = opunit_Sz(spaceconfig=scfg) Sp = opunit_Sp(spaceconfig=scfg) Sm = opunit_Sm(spaceconfig=scfg) wi = zeros((5, 5), dtype='O') wi[:, 0], wi[4, 1:] = (I, Sp, Sm, Sz, -h * Sz), (J / 2. * Sm, J / 2. * Sp, Jz * Sz, I) WL = [copy.deepcopy(wi) for i in xrange(nsite)] WL[0] = WL[0][4:] WL[-1] = WL[-1][:, :1] self.H_serial = WL2OPC(WL)
def __init__(self,J,Jz,h,nsite): self.spaceconfig=SpinSpaceConfig([2,1]) I=OpUnitI(hndim=2) Sx=opunit_Sx(spaceconfig=self.spaceconfig) Sy=opunit_Sy(spaceconfig=self.spaceconfig) Sz=opunit_Sz(spaceconfig=self.spaceconfig) SL,SZ=[],[] for i in xrange(nsite): Sxi,Syi,Szi=copy.copy(Sx),copy.copy(Sy),copy.copy(Sz) Sxi.siteindex=i Syi.siteindex=i Szi.siteindex=i SL.append(array([Sxi,Syi,sqrt(Jz/J)*Szi])) SZ.append(Szi) ops=[] for i in xrange(nsite): if i!=nsite-1: ops.append(J*SL[i].dot(SL[i+1])) ops.append(h[i]*SZ[i]) mpc=sum(ops) self.H_serial=mpc mpo=mpc.toMPO(method='direct') mpo.compress() self.H=mpo
def __init__(self,J1,J2,K,Jp,nsite,impurity_site=None): self.spaceconfig=SpinSpaceConfig([2,1]) if impurity_site is None: impurity_site=nsite/2 #nsite/2 and nsite/2-1 self.impurity_site=impurity_site self.J1,self.J2,self.K,self.Jp=J1,J2,K,Jp I=OpUnitI(hndim=self.spaceconfig.hndim) Sx=opunit_Sx(spaceconfig=self.spaceconfig) Sy=opunit_Sy(spaceconfig=self.spaceconfig) Sz=opunit_Sz(spaceconfig=self.spaceconfig) SL=[] for i in xrange(nsite): Sxi,Syi,Szi=copy.deepcopy(Sx),copy.deepcopy(Sy),copy.deepcopy(Sz) Sxi.siteindex=i Syi.siteindex=i Szi.siteindex=i SL.append(array([Sxi,Syi,Szi])) ops=[] for i in xrange(nsite-1): factor1=J1 if i==impurity_site or i==impurity_site-2: factor1*=Jp elif i==impurity_site-1: factor1*=K ops.append(factor1*SL[i].dot(SL[i+1])) if i<nsite-2 and i!=impurity_site-1 and i!=impurity_site-2: factor2=J2 if i==impurity_site-3 or i==impurity_site: factor2*=Jp ops.append(factor2*SL[i].dot(SL[i+2])) mpc=sum(ops) self.H_serial=mpc
def solve1(hl,nsite,config,Jz=1.,J=1.,save=True): ''' Run vMPS for Heisenberg model. ''' #generate the model print 'SOLVING %s'%config model=HeisenbergModel(J=J,Jz=Jz,h=hl,nsite=nsite) #run vmps #generate a random mps as initial vector spaceconfig=SpinSpaceConfig([2,1]) bmg=SimpleBMG(spaceconfig=spaceconfig,qstring='M') H=model.H.use_bm(bmg) k0=product_state(config=config,hndim=2,bmg=bmg) #setting up the engine vegn=VMPSEngine(H=H,k0=k0.toket(),eigen_solver='JD') eng,ket=vegn.run(endpoint=(6,'->',0),maxN=20,which='SL',nsite_update=2) #save to file if save: ind=sum(2**arange(nsite-1,-1,-1)*asarray(config)) filename='data/ket%s_h%.2fN%s.dat'%(ind,mean(hl),nsite) quicksave(filename,(eng,ket)) overlap=abs((k0.tobra()*ket).item()) print 'OVERLAP %s'%overlap return eng,ket,overlap
def measure_op(which,ket,usempi=False,ofile=None): ''' Get order parameter from ground states. Parameters: :which: str, * 'Sz', <Sz> :siteindices: list, the measure points. Return: array, the value of order parameter. ''' nsite=ket.nsite spaceconfig=SpinSpaceConfig([2,1]) ml=[] def measure1(siteindex): if which=='Sz': op=opunit_S(which='z',spaceconfig=spaceconfig,siteindex=siteindex) else: raise NotImplementedError() m=get_expect(op,ket=ket).item() #,bra=ket.tobra(labels=ket.labels)) print 'Get %s for site %s = %s @RANK: %s'%(which,siteindex,m,RANK) return m if usempi: ml=mpido(measure1,inputlist=siteindices) else: ml=[] for siteindex in arange(nsite): ml.append(measure1(siteindex)) ml=array(ml) if RANK==0 and ofile is not None: savetxt(ofile,ml.real) return ml
def __init__(self): nsite = 6 #number of sites hndim = 2 l = 0 vec = random.random(hndim**nsite) #a random state in form of 1D array. vec2 = random.random( hndim**nsite) #a random state in form of 1D array. mps = state2MPS(vec, sitedim=hndim, l=l, method='svd') #parse the state into a <MPS> instance. mps2 = state2MPS(vec2, sitedim=hndim, l=l, method='svd') #parse the state into a <MPS> instance. j1, j2 = 0.5, 0.2 scfg = SpinSpaceConfig([1, 2]) I = OpUnitI(hndim=hndim) Sz = opunit_Sz(spaceconfig=scfg) Sp = opunit_Sp(spaceconfig=scfg) Sm = opunit_Sm(spaceconfig=scfg) wi = zeros((4, 4), dtype='O') wi[0, 0], wi[1, 0], wi[2, 1], wi[3, 1:] = I, Sz, I, (j1 * Sz, j2 * Sz, I) WL = [deepcopy(wi) for i in xrange(nsite)] WL[0] = WL[0][3:4] WL[-1] = WL[-1][:, :1] mpo = WL2MPO(WL) self.mps, self.mps2 = mps, mps2 self.mpo = mpo self.vec, self.vec2 = vec, vec2 self.spaceconfig = scfg
def test_model2(): J, Jz = -3., 2 N1, N2 = 2, 3 scfg = SpinSpaceConfig([N1 * N2, 2]) config = array([1, 1, 0, 1, 1, 0]) #config=array([1,1,0,0,1,0,1,1,0]) #construct true H for periodic in [True, False]: h = HeisenbergH2D(N1, N2, J=J, Jz=Jz, periodic=periodic) H = FakeVMC(h).get_H() print 'Testing rmatmul of Hamiltonian(%s)' % ('PBC' if periodic else 'OBC') wl, flips = h._rmatmul(1 - 2 * config) configs = [] for flip in flips: nc = copy(1 - 2 * config) nc[asarray(flip)] *= -1 configs.append(nc) ss = SparseState(wl, configs) vec = ss.tovec(scfg) v0 = zeros(scfg.hndim) v0[scfg.config2ind(config)] = 1 v_true = v0.dot(H) assert_allclose(vec, v_true)
def test_Haldane(self): '''Solve model hamiltonians''' egn = ITEBDEngine(tol=1e-10) npart = 2 Dlist = arange(0, -0.6, -0.05) spaceconfig = SpinSpaceConfig([1, 3]) #the initial state GL = [] for i in xrange(npart): Gi = (0.5 - random.rand(1, 3, 1)) / 100. Gi[0, 2 * (i % 2), 0] = 1 GL.append(Gi) LL = [] for i in xrange(npart): LL.append(ones([1])) ivmps0 = IVMPS(GL=GL, LL=LL) mpsl, HL, EEL = [], [], [] for D in Dlist: H = self.get_Haldane(J=1., D=D) mps = egn.run(hs=H, ivmps=copy.copy(ivmps0), spaceconfig=spaceconfig, maxN=20) mpsl.append(mps) HL.append(H) print D, mps.LL[0][:4] SL, EL, ML1, ML2 = [], [], [], [] for mps, H in zip(mpsl, HL): mps2 = mps.roll(1) SL.append(mean(entanglement_entropy(mps))) print get_expect_ivmps(op=H, ket=mps), get_expect_ivmps(op=H, ket=mps2) EL.append( mean([ get_expect_ivmps(op=H, ket=mps), get_expect_ivmps(op=H, ket=mps2) ])) ML1.append( get_expect_ivmps( op=2 * opunit_S(which='z', siteindex=0, spaceconfig=spaceconfig), ket=mps)) ML2.append( get_expect_ivmps( op=2 * opunit_S(which='z', siteindex=0, spaceconfig=spaceconfig), ket=mps2)) ion() subplot(311) plot(Dlist, SL) subplot(312) plot(Dlist, array(EL)) subplot(313) plot(Dlist, array(ML1)) plot(Dlist, array(ML2)) pdb.set_trace()
def test_tovec(self): print 'Test @RBM.tovec' scfg = SpinSpaceConfig([2, 2]) configs = scfg.ind2config(arange(scfg.hndim)) vec = self.rbm.get_weight(1 - 2 * configs) assert_allclose(vec, self.vec, atol=1e-8) print 'Test Translational invariant @RBM.tovec.' vect = self.rbm_t.tovec(scfg) assert_allclose(vect, self.vec2, atol=1e-8)
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 __init__(self): a = [0.1j, 0.2] b = [0.1j, 0.2, 0.3] b2 = [-0.1j, 0.2, -0.3] W = [[0.1, -0.1, 0.1], [-0.1j, 0.1, 0.1j]] self.rbm = RBM(a, b, W) #translational invariant group tig = TIGroup(ngs=[2]) self.rbm_t = RBM(a, b2, W, group=tig) #get vec in the brute force way. self.vec = [] scfg1 = SpinSpaceConfig([2, 2]) scfg2 = SpinSpaceConfig([3, 2]) for i in xrange(scfg1.hndim): config1 = scfg1.ind2config(i) s = 1 - config1 * 2 vi = 0j for j in xrange(scfg2.hndim): config2 = scfg2.ind2config(j) h = 1 - 2 * config2 vi += exp((s * a).sum() + (h * b).sum() + s.dot(W).dot(h)) self.vec.append(vi) self.vec = array(self.vec) #the second vec self.vec2 = [] scfg1 = SpinSpaceConfig([2, 2]) scfg2 = SpinSpaceConfig([6, 2]) for i in xrange(scfg1.hndim): config1 = scfg1.ind2config(i) s = 1 - config1 * 2 vi = 0j for j in xrange(scfg2.hndim): config2 = scfg2.ind2config(j) h = 1 - 2 * config2 vi += exp((s * a).sum() + (s[::-1] * a).sum() + (h * concatenate([b2, b2])).sum() + s.dot(W).dot(h[:3]) + s[::-1].dot(W).dot(h[3:])) self.vec2.append(vi) self.vec2 = array(self.vec2)
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 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 solve_ed(hl,nsite,Jz=1.,J=1.): ''' Run ED for Heisenberg model. ''' #generate the model model=HeisenbergModel(J=J,Jz=Jz,h=hl,nsite=nsite) #run vmps #generate a random mps as initial vector spaceconfig=SpinSpaceConfig([2,1]) bmg=SimpleBMG(spaceconfig=spaceconfig,qstring='M') H=model.H_serial.H().real E,U=eigh(H) return E,U
def __init__(self, g, h, nsite, J=1): self.spaceconfig = SpinSpaceConfig([2, 1]) self.J, self.g, self.h, self.nsite = J, g, h, nsite scfg = self.spaceconfig I = OpUnitI(hndim=scfg.hndim) Sx = opunit_Sx(spaceconfig=scfg) * 2 Sz = opunit_Sz(spaceconfig=scfg) * 2 opc = 0 for i in range(nsite): hi = h - J if i == 0 or i == nsite - 1 else h opc = opc + (hi * Sz.as_site(i) + g * Sx.as_site(i)) if i != nsite - 1: opc = opc + J * Sz.as_site(i) * Sz.as_site(i + 1) self.opc = opc
def get_H(self): '''Get the target Hamiltonian Matrix.''' nsite,periodic=self.h.nsite,self.h.periodic scfg=SpinSpaceConfig([nsite,2]) if isinstance(self.h,TFI): Jz,h=self.h.Jz,self.h.h h2=Jz/4.*kron(sz,sz) H=0 for i in xrange(nsite): if i!=nsite-1: H=H+kron(kron(eye(2**i),h2),eye(2**(nsite-2-i))) elif periodic: #periodic boundary H=H+Jz/4.*kron(kron(sz,eye(2**(nsite-2))),sz) H=H+h/2.*kron(kron(eye(2**i),sx),eye(2**(nsite-i-1))) return H elif isinstance(self.h,HeisenbergH): J,Jz=self.h.J,self.h.Jz h2=J/4.*(kron(sx,sx)+kron(sy,sy))+Jz/4.*kron(sz,sz) H=0 for i in xrange(nsite-1): H=H+kron(kron(eye(2**i),h2),eye(2**(nsite-2-i))) #impose periodic boundary if periodic: H=H+J/4.*(kron(kron(sx,eye(2**(nsite-2))),sx)+kron(kron(sy,eye(2**(nsite-2))),sy))+Jz/4.*(kron(kron(sz,eye(2**(nsite-2))),sz)) return H elif isinstance(self.h,HeisenbergH2D): from tba.lattice import Square_Lattice J,Jz=self.h.J,self.h.Jz lattice=Square_Lattice(N=(self.h.N1,self.h.N2)) if self.h.periodic: lattice.set_periodic([True,True]) lattice.initbonds(5) b1s=lattice.getbonds(1) b1s=[b for b in b1s if b.atom1<b.atom2] H=0 if False: sx0=csr_matrix(sx) sy0=csr_matrix(sy) sz0=csr_matrix(sz) sx0,sy0,sz0=sx,sy,sz for b in b1s: for ss,Ji in zip([sx0,sy0,sz0],[J,J,Jz]): H=H+Ji/4.*kron(kron(kron(kron(eye(2**b.atom1),ss),eye(2**(b.atom2-b.atom1-1))),ss),eye(2**(lattice.nsite-b.atom2-1))) #H=H+Ji/4.*kron(kron(kron(kron(eye(2**(lattice.nsite-b.atom2-1)),ss),eye(2**(b.atom2-b.atom1-1))),ss),eye(2**(b.atom1))) #e,v=eigsh(H,k=1,which='SA') #print e/lattice.nsite return H
def test_ising(self): '''Solve model hamiltonians''' npart = 2 hlist = arange(0., 2, 0.1) spaceconfig = SpinSpaceConfig([1, 2]) #the initial state GL = [] for i in xrange(npart): Gi = Tensor(0.5 - 0.01 * ones([spaceconfig.hndim, 1, 1]), labels=['s%s' % i, 'a%s' % i, 'b%s' % i]) Gi[0, 0, 0] = 1 GL.append(Gi) GL[1].labels[1:] = GL[1].labels[1:][::-1] #print GL[0].labels #print GL[1].labels LL = [Link(['b0', 'b1'], ones([1])), Link(['a1', 'a0'], ones([1]))] mpsl, EEL, HL = [], [], [] for h in hlist: hb = self.get_Ising(h=2 * h, J=4.) egn = ITEBDEngine(hs=[hb] * 2, tol=1e-10) ivmps0 = IVMPS(tensors=GL, LL=LL) mps = egn.run(ivmps=ivmps0, maxN=5) mpsl.append(mps) HL.append(hb) ################# Get the exact energies ###################### f = lambda k, h: -2 * sqrt(1 + h**2 - 2 * h * cos(k)) / pi / 2. E0_exact = integrate.quad(f, 0, pi, args=(h, ))[0] EEL.append(E0_exact) SL, EL, ML = [], [], [] for mps, H in zip(mpsl, HL): SL.append(entanglement_entropy(mps)) #print get_expect_ivmps(op=H,ket=mps),get_expect_ivmps(op=H,ket=mps2) #EL.append(mean([get_expect_ivmps(op=H,ket=mps),get_expect_ivmps(op=H,ket=mps2)])) #ML.append(get_expect_ivmps(op=2*opunit_S(which='z',siteindex=0,spaceconfig=spaceconfig),ket=mps)) ion() subplot(311) #plot(hlist,abs(array(ML))) subplot(312) plot(hlist, SL) subplot(313) #plot(hlist,abs(array(EL)-EEL)) pdb.set_trace()
def __init__(self,J,Jz,h,nsite,nspin=3): self.spaceconfig=SpinSpaceConfig([1,nspin]) scfg=self.spaceconfig I=OpUnitI(hndim=scfg.hndim) Sx=opunit_Sx(spaceconfig=scfg) Sy=opunit_Sy(spaceconfig=scfg) Sz=opunit_Sz(spaceconfig=scfg) Sp=opunit_Sp(spaceconfig=scfg) Sm=opunit_Sm(spaceconfig=scfg) wi=zeros((5,5),dtype='O') #wi[:,0],wi[4,1:]=(I,Sp,Sm,Sz,-h*Sz),(J/2.*Sm,J/2.*Sp,Jz*Sz,I) wi[:,0],wi[4,1:]=(I,Sx,Sy,Sz,-h*Sz),(J*Sx,J*Sy,Jz*Sz,I) WL=[copy.deepcopy(wi) for i in xrange(nsite)] WL[0]=WL[0][4:] WL[-1]=WL[-1][:,:1] self.H=WL2MPO(WL) mpc=WL2OPC(WL) self.H_serial=mpc
def __init__(self,nsite,periodic,model='AFH'): self.nsite,self.periodic=nsite,periodic self.model=model if model=='AFH': self.h=HeisenbergH(nsite=nsite,J=-1.,Jz=1.,periodic=periodic) elif model=='AFH2D': N=int(sqrt(nsite)) self.h=HeisenbergH2D(N,N,J=-1.,Jz=1.,periodic=periodic) elif model=='TFI': self.h=TFI(nsite=nsite,Jz=-4.,h=-1.,periodic=periodic) else: raise ValueError() self.scfg=SpinSpaceConfig([nsite,2]) #vmc config c0=[-1,1]*(nsite/2); random.shuffle(c0) cgen=RBMConfigGenerator(initial_config=c0,nflip=2 if model[:3]=='AFH' else 1)#repeat([-1,1],(nsite/2))) self.vmc=VMC(cgen,nbath=500*nsite,nsample=5000*nsite,nmeasure=nsite,sampling_method='metropolis')
def __init__(self,nsite,periodic,model='AFH'): self.nsite,self.periodic=nsite,periodic self.model=model if model=='AFH': self.h=HeisenbergH(nsite=nsite,J=1.,Jz=1.,periodic=periodic) elif model=='TFI': self.h=TFI(nsite=nsite,Jz=-4.,h=-1.,periodic=periodic) elif model=='AFH2D': N1=N2=int(sqrt(nsite)) self.h=HeisenbergH2D(N1,N2,J=1.,Jz=1.,periodic=periodic) else: raise ValueError() self.scfg=SpinSpaceConfig([nsite,2]) self.fv=FakeVMC(self.h) #vmc config cgen=RBMConfigGenerator(initial_config=[-1,1]*(nsite/2)+[1]*(nsite%2),nflip=2 if model=='AFH' else 1) self.vmc=VMC(cgen,nbath=500*nsite,nsample=5000*nsite,nmeasure=nsite,sampling_method='metropolis')
def __init__(self,J,Jz,h,N1,N2,nspin=3): self.spaceconfig=SpinSpaceConfig([1,nspin]) scfg=self.spaceconfig I=OpUnitI(hndim=scfg.hndim) Sx=opunit_Sx(spaceconfig=scfg) Sy=opunit_Sy(spaceconfig=scfg) Sz=opunit_Sz(spaceconfig=scfg) Sp=opunit_Sp(spaceconfig=scfg) Sm=opunit_Sm(spaceconfig=scfg) opc=OpCollection() lt=Square_Lattice((N1,N2)) lt.set_periodic([True,True]) lt.initbonds(5) bonds=[b for b in lt.getbonds(1) if b.atom2>b.atom1] for b in bonds: atom1,atom2=b.atom1,b.atom2 opc+=J*(Sx.as_site(atom1)*Sx.as_site(atom2)+Sy.as_site(atom1)*Sy.as_site(atom2)) opc+=Jz*(Sz.as_site(atom1)*Sz.as_site(atom2)) for i in xrange(lt.nsite): opc=opc+h*Sz.as_site(i) mpo=opc.toMPO(nsite=lt.nsite,method='direct') self.H=mpo
def __init__(self): J = 1. nsite = 4 self.scfg = SpinSpaceConfig([nsite, 2]) #construct true H I2, I4 = eye(2), eye(4) h2 = J / 4. * (kron(sx, sx) + kron(sz, sz) + kron(sy, sy)) #construct operator H act on config self.h1 = TFI(nsite=4) self.h2 = HeisenbergH(nsite=4) self.toy1, self.toy2 = FakeVMC(self.h1), FakeVMC(self.h2) self.H1, self.H2 = self.toy1.get_H(), self.toy2.get_H() self.pW = PartialW() #generate a random rbm and the corresponding vector v self.rbm = random_rbm(nin=nsite, nhid=nsite) self.v = self.rbm.tovec(self.scfg) self.rbm_g = random_rbm(nin=nsite, nhid=nsite, group=TIGroup(4)) self.v_g = self.rbm_g.tovec(self.scfg)
def test_compress(): scfg=SpinSpaceConfig([4,2]) ss=SparseState([0.1j,0.2,0.3],[[1,1,0,1],[1,0,1,0],[1,1,0,1]]) assert_allclose(ss.ws,[0.2,0.3+0.1j]) assert_allclose(ss.configs,[[1,0,1,0],[1,1,0,1]])
def test_vec2sstate(): print 'Testing @vec2sstate, @SparseState.tovec' scfg=SpinSpaceConfig([4,2]) vec=2*random.random(scfg.hndim)-1 assert_allclose(vec2sstate(vec,scfg).tovec(scfg),vec,atol=1e-8)
def __init__(self,h): self.h=h self.scfg=scfg=SpinSpaceConfig([h.nsite,2])
def test_randomrbm(): nsite = 6 scfg = SpinSpaceConfig([nsite, 2]) rbm = random_rbm(nin=nsite, nhid=2) print rbm.tovec(scfg)
4. Get <H> under kA. ''' from numpy import sqrt, Inf from mpslib import random_bmps from opstring import OpCollection from mpo import OPC2MPO from mpolib import opunit_S from tba.hgen import SpinSpaceConfig from contraction import Contractor from pymps.blockmarker import SimpleBMG ########### Generate a random State ###### # the single site Hilbert space(Spin) config, 2 spin, 1 orbital. spaceconfig = SpinSpaceConfig([1, 2]) # the generator of block marker, # using magnetization `M = nup-ndn` as good quantum number. bmg = SimpleBMG(spaceconfig=spaceconfig, qstring='M') # generate a random mps of 10 site and chi = 20, # which is under the supervise of above <BlockMarkerGenerator>. kA = random_bmps(bmg=bmg, nsite=10, maxN=20) # nomalize it kA = kA / sqrt(kA.tobra() * kA).item() ########### Get the Good quantum Number ###### # number of steps, tolerence, maximum bond dimension. kA << kA.nsite, 1e-8, Inf # get the block marker, # the (quantum number)flow direction is left->right, # so the right most bond contains the final good quantum number.