def print_Hamiltonian(H_): mu = 0 for (A,h,imp,gmp) in H_: nact = len(A) print "term ",mu print "active qubits ",A print "operators: " for m in np.where(np.abs(h)>1e-8)[0]: print Opp2Str(Int2Bas(m,4,nact)),h[m] mu += 1
def print_Hamiltonian(H_):
mu = 0
for (A, h, imp, gmp) in H_:
#print('A: ',A)
nact = len(A)
print("active qubits ", A)
print("operators: ")
for m in np.where(np.abs(h) > 1e-8)[0]:
print(Opp2Str(Int2Bas(m, 4, nact)), h[m])
mu += 1
def pauli_basis(nbit_):
M = 4**nbit_
for i in range(M):
print(i, Opp2Str(Int2Bas(i, 4, nbit_)))
elif Oppstr == "ZX":
return "Y", 1j
elif Oppstr == "ZY":
return "X", -1j
elif Oppstr == "ZZ":
return "I", 1
else:
raise ValueError
def lie_algebra(mu, nu, n):
# Return coefficients and index for sigma mu,sigma nu
index = ''
coeff = 1
for i in range(n):
tmpA, tmpB = PPmunu(mu[i] + nu[i])
index += tmpA
coeff *= tmpB
return coeff, Bas2Int(Str2Opp(index), 4)
if __name__ == '__main__':
n = 2
index = np.zeros([4**n, 4**n], dtype=int)
coeff = np.zeros([4**n, 4**n], dtype=complex)
for i in range(4**n):
for j in range(4**n):
coeff[i, j], index[i, j] = lie_algebra(Opp2Str(Int2Bas(i, 4, n)),
Opp2Str(Int2Bas(j, 4, n)),
n)
print(i, j, index[i, j])
e = np.matmul(Hamiltonian, phi)
e = np.real(np.matmul(np.transpose(np.conj(phi)), e))
energy_classical_list.append(e)
print('Final energy at beta', beta, 'is ', e)
# Qite approximation
# First populate the Lie algebra rules
index = np.zeros([4**2, 4**2], dtype=int)
coeff = np.zeros([4**2, 4**2], dtype=complex)
row = 0
for i in range(4**2):
column = 0
for j in range(4**2):
Pnu = Opp2Str(Int2Bas(column, 4, 2))
Pmu = Opp2Str(Int2Bas(row, 4, 2))
A = Pmu[0] + Pnu[0]
B = Pmu[1] + Pnu[1]
A, intA = PPmunu(A)
B, intB = PPmunu(B)
index[i, j] = Bas2Int(Str2Opp(A + B), 4)
coeff[i, j] = intA * intB
column += 1
row += 1
#
phi = psi
# Store the energy for initial wavefunction
e = np.matmul(Hamiltonian, phi)
e = np.real(np.matmul(np.transpose(np.conj(phi)), e))