def test_coupling_terms_multimode(self):
qubit = Transmon("qubit", levels=3, kerr=-200e-3)
cavity1 = Cavity("cavity1", levels=10, kerr=-10e-6)
cavity2 = Cavity("cavity2", levels=6, kerr=-10e-6)
system = System("system", modes=[qubit, cavity2, cavity1])
system.set_cross_kerr(qubit, cavity1, -2e-3)
system.set_cross_kerr(qubit, cavity2, -1e-3)
system.set_cross_kerr(cavity1, cavity2, -5e-6)
self.assertEqual(len(system.couplings()), 3)
for modes in [[qubit, cavity1], [qubit, cavity1, cavity2]]:
with system.use_modes(modes):
self.assertEqual(
system.couplings()[0], 2 * np.pi * -2e-3 * qubit.n * cavity1.n
)
for i, modes in enumerate([[qubit, cavity2], [qubit, cavity1, cavity2]]):
with system.use_modes(modes):
self.assertEqual(
system.couplings()[i], 2 * np.pi * -1e-3 * qubit.n * cavity2.n
)
for i, modes in enumerate([[cavity2, cavity1], [qubit, cavity1, cavity2]]):
with system.use_modes(modes):
self.assertEqual(
system.couplings()[2 * i], 2 * np.pi * -5e-6 * cavity1.n * cavity2.n
)
def test_coupling_terms(self):
qubit = Transmon("qubit", levels=3, kerr=-200e-3)
cavity = Cavity("cavity", levels=10, kerr=-10e-6)
system = System("system", modes=[qubit, cavity])
chi = -2e-3
key = frozenset([qubit.name, cavity.name])
system.coupling_terms[key].append(
CouplingTerm(qubit, "n", cavity, "n", strength=2 * np.pi * chi)
)
self.assertEqual(len(system.couplings()), 1)
self.assertEqual(system.couplings()[0], 2 * np.pi * chi * qubit.n * cavity.n)
system.set_cross_kerr(qubit, cavity, chi)
self.assertEqual(len(system.couplings()), 1)
self.assertEqual(system.couplings()[0], 2 * np.pi * chi * qubit.n * cavity.n)
def test_set_cross_kerr(self):
qubit = Transmon("qubit", levels=3, kerr=-200e-3)
cavity = Cavity("cavity", levels=10, kerr=-10e-6)
system = System("system", modes=[qubit, cavity])
with self.assertRaises(ValueError):
system.set_cross_kerr(qubit, qubit, -1e-3)
chi = -2e-3
system.set_cross_kerr(qubit, cavity, chi)
self.assertEqual(len(system.couplings()), 1)
self.assertEqual(system.couplings()[0], 2 * np.pi * chi * qubit.n * cavity.n)
system.set_cross_kerr(qubit, cavity, chi)
self.assertEqual(len(system.couplings()), 1)
self.assertEqual(system.couplings()[0], 2 * np.pi * chi * qubit.n * cavity.n)
system.set_cross_kerr(cavity, qubit, chi)
self.assertEqual(len(system.couplings()), 1)
self.assertEqual(system.couplings()[0], 2 * np.pi * chi * qubit.n * cavity.n)
