2010/09/30 by A. R. Akhmerov, J. P. Dahlhaus, F. Hassler +2 · 2 citations
Physics and Astronomy · #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevlett.106.057001
published as Phys. Rev. Lett. 106, 057001 (2011) · 7 pages, 4 figures; v3: added appendix with numerics for long-range disorder
arxiv created 2010/11/30 · arxiv updated 2013/07/09
Superconducting wires without time-reversal and spin-rotation symmetries can be driven into a topological phase that supports Majorana bound states. Direct detection of these zero-energy states is complicated by the proliferation of low-lying excitations in a disordered multi-mode wire. We show that the phase transition itself is signaled by a quantized thermal conductance and electrical shot noise power, irrespective of the degree of disorder. In a ring geometry, the phase transition is signaled by a period doubling of the magnetoconductance oscillations. These signatures directly follow from the identification of the sign of the determinant of the reflection matrix as a topological quantum number.