Exemplo n.º 1
0
    def test_dv_dtype(self):

        D = ch.QuantumState(ch._vec(np.eye(2, dtype=np.complex128) * .5), 'dv')
        self.assertEqual(type(D._dv.density_vector),
                         type(np.array([])))  #Changed Type
        self.assertEqual(D._dv.density_vector.dtype, np.complex128)

        D = ch.QuantumState(ch._vec(np.eye(2) * .5), 'dv')
        self.assertEqual(type(D._dv.density_vector),
                         type(np.array([])))  #Changed Type
        self.assertEqual(D._dv.density_vector.dtype, np.complex128)

        self.assertEqual(type(D.density_vector()),
                         type(np.array([])))  #Changed Type
        self.assertEqual(D.density_vector().dtype, np.complex128)

        self.assertEqual(type(D.density_matrix()),
                         type(np.array([])))  #Changed Type
        self.assertEqual(D.density_matrix().dtype, np.complex128)

        self.assertEqual(type(D.bloch_vector()),
                         type(np.array([])))  #Changed Type
        self.assertEqual(D.bloch_vector().dtype, np.float64)

        w, b = D.state_mixture()
        self.assertEqual(type(w), np.ndarray)
        self.assertEqual(w.dtype, np.float64)
        self.assertTrue(all([type(bb) == type(np.array([]))
                             for bb in b]))  #Changed Type
        self.assertTrue(all([bb.dtype == np.complex128 for bb in b]))
Exemplo n.º 2
0
    def test_kraus_to_all(self):
        paulis = [ch._sigmaI, ch._sigmaX, ch._sigmaY, ch._sigmaZ]
        weights = np.random.randn(4) + 1j * np.random.randn(4)
        weights = weights / la.norm(weights)

        kraus = [w * p for w, p in zip(weights, paulis)]
        D = ch.QuantumChannel(kraus, 'kraus')
        kraus2 = D.kraus()
        errs = [la.norm(k1 - k2) for k1, k2 in zip(kraus, kraus2)]
        self.assertEqual(np.max(errs), 0)

        S = np.zeros((8, 2), dtype=np.complex128)
        for i in range(4):
            S[i * 2:(i + 1) * 2, :] = kraus[i]

        D = ch.QuantumChannel(kraus, 'kraus')
        S2 = D.stiefel()
        self.assertEqual(la.norm(S - S2), 0)

        S = np.zeros((8, 2), dtype=np.complex128)
        for i in range(4):
            S[i::4, :] = kraus[i]

        D = ch.QuantumChannel(kraus, 'kraus')
        S2 = D.stiefel2()
        self.assertEqual(la.norm(S - S2), 0)

        D = ch.QuantumChannel(kraus, 'kraus')
        L = np.sum([
            w.conj() * w * np.kron(p.conj(), p)
            for w, p in zip(weights, paulis)
        ], 0)
        L2 = D.liouvillian()
        self.assertAlmostEqual(la.norm(L - L2), 0, 15)

        ptms = [np.eye(4) for _ in paulis]
        for i in range(1, 4):
            for j in range(1, 4):
                if i != j:
                    ptms[i][j, j] = -1

        PTM = np.sum([w.conj() * w * p for w, p in zip(weights, ptms)], 0)
        D = ch.QuantumChannel(kraus, 'kraus')
        PTM2 = D.ptm()
        self.assertAlmostEqual(la.norm(PTM - PTM2), 0)

        choi = np.sum([
            w.conj() * w * ch._vec(p) * ch._vec(p).conj().T
            for w, p in zip(weights, paulis)
        ], 0)
        D = ch.QuantumChannel(kraus, 'kraus')
        choi2 = D.choi()
        self.assertAlmostEqual(la.norm(choi - choi2), 0)

        chi = np.diag([w.conj() * w for w in weights])
        D = ch.QuantumChannel(kraus, 'kraus')
        chi2 = D.chi()
        self.assertAlmostEqual(la.norm(chi - chi2), 0, 15)
Exemplo n.º 3
0
    def test_ptm_to_all(self):
        paulis = [ch._sigmaI, ch._sigmaX, ch._sigmaY, ch._sigmaZ]
        weights = np.random.randn(4) + 1j * np.random.randn(4)
        weights = weights / la.norm(weights)

        ptms = [np.eye(4) for _ in paulis]
        for i in range(1, 4):
            for j in range(1, 4):
                if i != j:
                    ptms[i][j, j] = -1

        PTM = np.sum([w.conj() * w * p for w, p in zip(weights, ptms)], 0)
        D = ch.QuantumChannel(PTM, 'ptm')
        PTM2 = D.ptm()
        self.assertEqual(la.norm(PTM - PTM2), 0)

        kraus = [w * p for w, p in zip(weights, paulis)]

        D = ch.QuantumChannel(PTM, 'ptm')
        kraus2 = D.kraus()
        #errs = [la.norm(k1-k2) for k1,k2 in zip(kraus,kraus2)]
        errs = [
            np.min([
                la.norm(np.kron(k1.conj(), k1) - np.kron(k2.conj(), k2))
                for k2 in kraus2
            ]) for k1 in kraus
        ]
        self.assertAlmostEqual(la.norm(errs), 0, 12)

        #Skip stiefel since it is tedious due to phase ambiguity
        #S = np.zeros((8,2),dtype=np.complex128)
        #for i in range(4):
        #    S[i*2:(i+1)*2,:] = kraus[i]
        D = ch.QuantumChannel(PTM, 'ptm')
        S2 = D.stiefel()
        #errs = [np.min([la.norm(np.kron(k1.conj(),k1)-np.kron(k2.conj(),k2)) for k2 in kraus2]) for k1 in kraus]
        #self.AssertEqual(la.norm(S-S2),0)

        D = ch.QuantumChannel(PTM, 'ptm')
        L = np.sum([
            w.conj() * w * np.kron(p.conj(), p)
            for w, p in zip(weights, paulis)
        ], 0)
        L2 = D.liouvillian()
        self.assertAlmostEqual(la.norm(L - L2), 0, 12)

        choi = np.sum([
            w.conj() * w * ch._vec(p) * ch._vec(p).conj().T
            for w, p in zip(weights, paulis)
        ], 0)
        D = ch.QuantumChannel(PTM, 'ptm')
        choi2 = D.choi()
        self.assertAlmostEqual(la.norm(choi - choi2), 0, 12)

        chi = np.diag([w.conj() * w for w in weights])
        D = ch.QuantumChannel(PTM, 'ptm')
        chi2 = D.chi()
        self.assertAlmostEqual(la.norm(chi - chi2), 0, 12)
Exemplo n.º 4
0
    def test_liou_to_choi(self):

        paulis = [ch._sigmaI, ch._sigmaX, ch._sigmaY, ch._sigmaZ]
        for i, gate in enumerate(paulis):
            L = np.kron(gate.conj(), gate)
            D = ch.QuantumChannel(L, 'liou')
            choi = D.choi()
            choi_true = ch._vec(gate) * ch._vec(gate).conj().T

            self.assertEqual(la.norm(choi - choi_true), 0)
Exemplo n.º 5
0
    def test_dv_to_dv(self):

        G = np.random.randn(2, 2) + 1j * np.random.randn(2, 2)
        Q, R = la.qr(G)
        d = np.random.rand(2)
        d = d / np.sum(d)
        Q = np.array(Q)
        dm = np.dot(Q, np.dot(np.diag(d), Q.conj().T))

        dv = ch._vec(dm)

        p = ch.QuantumState(dv, 'dv')

        err1 = la.norm(dv - p.density_vector())
        self.assertEqual(err1, 0)

        dm = p.density_matrix()
        p2 = ch.QuantumState(dm, 'dm')

        err2 = la.norm(dv - p2.density_vector())
        self.assertEqual(err2, 0)

        bv = p.bloch_vector()
        self.assertLessEqual(la.norm(bv), 1.)

        p3 = ch.QuantumState(bv, 'bv')
        err3 = la.norm(dv - p3.density_vector())
        self.assertAlmostEqual(err3, 0, 12)

        w, b = p.state_mixture()
        p4 = ch.QuantumState((w, b), 'sm')
        err4 = la.norm(dv - p4.density_vector())
        self.assertAlmostEqual(err4, 0, 12)