bachelor_thesis/presentation/spin_chain/hamiltonian.py
2020-04-21 12:41:03 +02:00

29 lines
667 B
Python

import numpy as np
I = np.matrix([[1, 0], [0, 1]])
Z = np.matrix([[1, 0], [0, -1]])
X = np.matrix([[0, 1], [1, 0]])
def Mi(nqbits, i, M):
result = 1
for j in range(nqbits):
if(j != i):
result = np.kron(result, I)
else:
result = np.kron(result, M)
return result
def H_interaction(nqbits):
interaction_terms = [Mi(nqbits, i, Z) @ Mi(nqbits, i+1, Z) for i in range(nqbits - 1)]
return sum(interaction_terms)
def H_field(nqbits, g):
field_terms = [g*Mi(nqbits, i, X) for i in range(nqbits)]
return sum(field_terms)
def H(nqbits, g):
return (-H_interaction(nqbits) + H_field(nqbits, g)).real