English

Topological Phase Transition driven by Infinitesimal Instability: Majorana Fermions in Non-Hermitian Spintronics

Mesoscale and Nanoscale Physics 2019-09-02 v3 Materials Science Quantum Gases Superconductivity Quantum Physics

Abstract

Quantum phase transitions are intriguing and fundamental cooperative phenomena in physics. Analyzing a superconducting nanowire with spin-dependent non-Hermitian hopping, we discover a topological quantum phase transition driven by infinitesimal cascade instability. The anomalous phase transition is complementary to the universal non-Bloch wave behavior of non-Hermitian systems. We show that an infinite small magnetic field drastically suppresses the non-Hermitian skin effect, inducing a topological phase with Majorana boundary states. Furthermore, by identifying the bulk topological invariant, we establish the non-Hermitian bulk-boundary correspondence that does not have a Hermitian counterpart. We also discuss an experimental realization of the system by using the spin-current injection to a quantum wire.

Keywords

Cite

@article{arxiv.1904.06355,
  title  = {Topological Phase Transition driven by Infinitesimal Instability: Majorana Fermions in Non-Hermitian Spintronics},
  author = {Nobuyuki Okuma and Masatoshi Sato},
  journal= {arXiv preprint arXiv:1904.06355},
  year   = {2019}
}

Comments

6+4 pages, 3+1 figures