scattering.py 文件源码

def eigenbasis(self, nb, phi=0):
        """
        Calculates the generalized eigen-energies along with
        the left and right eigen-basis.

        Parameters
        ----------
        nb : int
            Number of bosons
        phi : float
            Phase factor for the relevant photonic state
        """
        phi = 0 if self.local else phi

        ckey = '{}-{}'.format(nb, phi)
        if ckey not in self._cache['eigen']:
            # generate number sector
            ns1 = self.model.numbersector(nb)

            # get the size of the basis
            ns1size = ns1.basis.len  # length of the number sector basis
            # G1i = xrange(ns1size)    # our Greens function?

            # self energy
            sigma = self.sigma(nb, phi)

            # Effective Hamiltonian
            H1n = ns1.hamiltonian + sigma

            # Complete diagonalization
            E1, psi1r = linalg.eig(H1n.toarray(), left=False)
            psi1l = np.conj(np.linalg.inv(psi1r)).T

            # check for dark states (throw a warning if one shows up)
            # if (nb > 0):
            #     Setup.check_for_dark_states(nb, E1)

            self._cache['eigen'][ckey] = (E1, psi1l, psi1r)

        return self._cache['eigen'][ckey]