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binomial

Cat Code Qubit

BinomialQubit

Bases: BosonicQubit

Cat Qubit Class.

Source code in jaxquantum/codes/binomial.py 
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class BinomialQubit(BosonicQubit):
    """
    Cat Qubit Class.
    """

    name = "binomial"

    def _params_validation(self):
        super()._params_validation()

        # notation https://arxiv.org/pdf/2010.08699.pdf
        if "L" not in self.params:
            self.params["L"] = 1
        if "G" not in self.params:
            self.params["G"] = 0
        if "D" not in self.params:
            self.params["D"] = 0

    def _get_basis_z(self) -> Tuple[jqt.Qarray, jqt.Qarray]:
        """
        Construct basis states |+-x>, |+-y>, |+-z>
        """
        N = self.params["N"]

        L = self.params["L"]
        G = self.params["G"]
        D = self.params["D"]

        S = L + G

        M = jnp.max(jnp.array([L, G, 2 * D]))

        def plus_z_gen(p):
            C = comb(M + 1, p)
            return jnp.sqrt(C) * jqt.basis(N, p * (S + 1)).data

        plus_z = jnp.sum(vmap(plus_z_gen)(jnp.arange(0, M + 2, 2)), axis=0)
        plus_z = jqt.unit(jqt.Qarray.create(plus_z))

        def minus_z_gen(p):
            C = comb(M + 1, p)
            return jnp.sqrt(C) * jqt.basis(N, p * (S + 1)).data

        minus_z = jnp.sum(vmap(minus_z_gen)(jnp.arange(1, M + 2, 2)), axis=0)
        minus_z = jqt.unit(jqt.Qarray.create(minus_z))

        return plus_z, minus_z