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Numerical study of spin quantum Hall transitions in superconductors with broken time-reversal symmetry

Qinghong Cui·Xin Wan·Kun Yang
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Abstract

We present results of numerical studies of spin quantum Hall transitions in disordered superconductors, in which the pairing order parameter breaks time-reversal symmetry. We focus mainly on p-wave superconductors in which one of the spin components is conserved. The transport properties of the system are studied by numerically diagonalizing pairing Hamiltonians on a lattice, and by calculating the Chern and Thouless numbers of the quasiparticle states. We find that in the presence of disorder, (spin-)current carrying states exist only at discrete critical energies in the thermodynamic limit, and the spin-quantum Hall transition driven by an external Zeeman field has the same critical behavior as the usual integer quantum Hall transition of non-interacting electrons. These critical energies merge and disappear as disorder strength increases, in a manner similar to those in lattice models for integer quantum Hall transition.

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Qinghong Cui, Xin Wan, Kun Yang. 2004-10-19. Numerical study of spin quantum Hall transitions in superconductors with broken time-reversal symmetry. https://doi.org/10.1103/physrevb.70.094506

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