def TransverseIsing(nspin, R, J, h):
H = []
for i in range(nspin):
j = (i + 1) % nspin
active = [
k for k in range(nspin)
if dpbc(i, k, nspin) < R or dpbc(j, k, nspin) < R
]
active = np.asarray(active)
print(active)
nact = len(active)
h_alpha = np.zeros(4**nact)
ii = np.where(active == i)[0][0]
jj = np.where(active == j)[0][0]
idx = [0] * nact
idx[ii] = 1
h_alpha[Bas2Int(idx, 4)] = h
idx = [0] * nact
idx[ii] = 3
idx[jj] = 3
if np.abs(i - j) == 1 and j != 0:
h_alpha[Bas2Int(idx, 4)] = J
imap, gmap = pauli_action(active, nspin)
H.append((active, h_alpha, imap, gmap))
Hm = Hmat(H)
print()
print_Hamiltonian(H)
return H
def Heisenberg_SR(nspin, R):
H = []
imax = nspin
if (nspin == 2): imax = nspin - 1
for i in range(imax):
j = (i + 1) % nspin
active = [
k for k in range(nspin)
if dpbc(i, k, nspin) < R or dpbc(j, k, nspin) < R
]
active = np.asarray(active)
nact = len(active)
# -----
h_alpha = np.zeros(4**nact)
ii = np.where(active == i)[0][0]
jj = np.where(active == j)[0][0]
for alpha in range(1, 4):
idx = [0] * nact
idx[ii] = alpha
idx[jj] = alpha
h_alpha[Bas2Int(idx, 4)] = 1.0
# -----
imap, gmap = pauli_action(active, nspin)
H.append((active, h_alpha, imap, gmap))
return H
def Ising(nspin,R,psi): H = [] for i in range(nspin): j = (i+1)%nspin # ----- active = [k for k in range(nspin) if dpbc(i,k,nspin)<R or dpbc(j,k,nspin)<R] active = np.asarray(active) nact = len(active) # ----- h_alpha = np.zeros(4**nact) ii = np.where(active==i)[0][0] jj = np.where(active==j)[0][0] idx = [0]*nact idx[ii] = 3 h_alpha[Bas2Int(idx,4)] = np.sin(psi)/2.0 idx = [0]*nact idx[jj] = 3 h_alpha[Bas2Int(idx,4)] = np.sin(psi)/2.0 idx = [0]*nact idx[ii] = 1 idx[jj] = 1 h_alpha[Bas2Int(idx,4)] = np.cos(psi) # ----- imap,gmap = pauli_action(active,nspin) H.append((active,h_alpha,imap,gmap)) return H