def eval_vbond(pepsa0, pepsa, i, j, auxbond):
debug = False
# Sz*Sz
pepsb = peps.copy(pepsa)
pepsb[i, j] = einsum("pq,qludr->pludr", Sz, pepsa[i, j])
pepsb[i + 1, j] = einsum("pq,qludr->pludr", Sz, pepsa[i + 1, j])
valzz = peps.dot(pepsa0, pepsb, auxbond)
if debug: print(i, j), 'valzz=', valzz
# Sp*Sm
pepsb = peps.copy(pepsa)
pepsb[i, j] = einsum("xpq,qludr->plxudr", Sp,
pepsa[i, j]).merge_adjpair(2, 3)
pepsb[i + 1, j] = einsum("xpq,qludr->pluxdr", Sm,
pepsa[i + 1, j]).merge_adjpair(3, 4)
valpm = peps.dot(pepsa0, pepsb, auxbond)
if debug: print(i, j), 'valpm=', valpm
# Sm*Sp
pepsb = peps.copy(pepsa)
pepsb[i, j] = einsum("xpq,qludr->plxudr", Sm,
pepsa[i, j]).merge_adjpair(2, 3)
pepsb[i + 1, j] = einsum("xpq,qludr->pluxdr", Sp,
pepsa[i + 1, j]).merge_adjpair(3, 4)
valmp = peps.dot(pepsa0, pepsb, auxbond)
if debug: print(i, j), 'valmp=', valmp
return valzz + 0.5 * (valpm + valmp)
def test_conf():
np.random.seed(5)
nr = 3
nc = 3
pdim = 2
bond = 2
auxbond = 4
# Initialization:
# [[0 1 0 1]
# [1 0 1 0]
# [0 1 0 1]
# [1 0 1 0]
# [0 1 0 1]
# [1 0 1 0]]
configa = np.zeros([nr, nc], dtype=np.int)
for i in range(nr):
for j in range(nc):
configa[i, j] = (i + j) % 2
pepsa = peps.create(pdim, configa)
#for i in range(nr):
# for j in range(nc):
# print '(i,j)=',(i,j)
# pepsa[i,j].prt()
print "CEVAL =", peps.ceval(pepsa, configa, auxbond)
PP = peps.dot(pepsa, pepsa, None)
print "<P|P> =", PP
Sp = peps_h.get_Sp()
Sm = peps_h.get_Sm()
Sz = peps_h.get_Sz()
i = j = 0
# Sm*Sp
pepsb = peps.copy(pepsa)
pepsb[i, j] = einsum("xpq,qludr->plxudr", Sm,
pepsa[i, j]).merge_adjpair(2, 3)
pepsb[i, j].prt()
pepsb[i, j + 1] = einsum("xpq,qludr->pluxdr", Sp,
pepsa[i, j + 1]).merge_adjpair(3, 4)
valmp = peps.dot(pepsb, pepsa, auxbond)
print 'valmp=', valmp
# Sz*Sz
pepsb = peps.copy(pepsa)
pepsb[i, j] = einsum("pq,qludr->pludr", Sz, pepsa[i, j])
pepsb[i, j + 1] = einsum("pq,qludr->pludr", Sz, pepsa[i, j + 1])
valzz = peps.dot(pepsb, pepsa, auxbond)
print 'valzz=', valzz
# Sp*Sm
pepsb = peps.copy(pepsa)
pepsb[i, j] = einsum("xpq,qludr->plxudr", Sp,
pepsa[i, j]).merge_adjpair(2, 3)
pepsb[i, j + 1] = einsum("xpq,qludr->pluxdr", Sm,
pepsa[i, j + 1]).merge_adjpair(3, 4)
valpm = peps.dot(pepsb, pepsa, auxbond)
print 'valpm=', valpm
return 0
def eval_vbond(pepsa0, pepsa, i, j, auxbond):
pepsb = peps.copy(pepsa)
pepsb[i, j] = einsum("pq,qludr->pludr", Sz, pepsa[i, j])
pepsb[i + 1, j] = einsum("pq,qludr->pludr", Sz, pepsa[i + 1, j])
valzz = peps.dot(pepsa0, pepsb, auxbond)
pepsb = peps.copy(pepsa)
pepsb[i, j] = einsum("pq,qludr->pludr", Sp, pepsa[i, j])
pepsb[i + 1, j] = einsum("pq,qludr->pludr", Sm, pepsa[i + 1, j])
valpm = peps.dot(pepsa0, pepsb, auxbond)
pepsb = peps.copy(pepsa)
pepsb[i, j] = einsum("pq,qludr->pludr", Sm, pepsa[i, j])
pepsb[i + 1, j] = einsum("pq,qludr->pludr", Sp, pepsa[i + 1, j])
valmp = peps.dot(pepsa0, pepsb, auxbond)
return valzz + .5 * (valpm + valmp)