def test_tunneling():
"Tunneling operator"
N = 5
tn = tunneling(2*N+1)
tn_matrix = np.diag(np.ones(2*N),k=-1) + np.diag(np.ones(2*N),k=1)
assert_equal(np.allclose(tn.full(), tn_matrix), True)
tn = tunneling(2*N+1,2)
tn_matrix = np.diag(np.ones(2*N-1),k=-2) + np.diag(np.ones(2*N-1),k=2)
assert_equal(np.allclose(tn.full(), tn_matrix), True)
def test_tunneling():
"Tunneling operator"
N = 5
tn = tunneling(2*N+1)
tn_matrix = np.diag(np.ones(2*N),k=-1) + np.diag(np.ones(2*N),k=1)
assert_equal(np.allclose(tn.full(), tn_matrix), True)
tn = tunneling(2*N+1,2)
tn_matrix = np.diag(np.ones(2*N-1),k=-2) + np.diag(np.ones(2*N-1),k=2)
assert_equal(np.allclose(tn.full(), tn_matrix), True)
def calc_Hj_cb(self, phi):
"""
Calculate Josephson energy in charge bassis.
phi = pi Flux/Flux_quantum
Returns
-------
qp.Qobj
"""
scalar = - np.sign(np.cos(phi))*self.Ej * \
self._phi_coeff(phi) / 2
op = qp.tunneling(self.space_dim, 1)
return scalar * op
def test_tunneling_type():
"Operator CSR Type: tunneling"
op = tunneling(5)
assert_equal(isspmatrix_csr(op.data), True)
def test_tunneling_type():
"Operator CSR Type: tunneling"
op = tunneling(5)
assert_equal(isspmatrix_csr(op.data), True)
def H_J(E_j,N):
return -E_j/2*qp.tunneling(2*N+1,1)
def test_tunneling(shift):
N = 10
tn = qutip.tunneling(N, shift)
tn_matrix = np.diag(np.ones(N - shift), k=shift)
tn_matrix += tn_matrix.T
np.testing.assert_allclose(tn.full(), tn_matrix)
