Proximity effect and Majorana bound states in clean semiconductor nanowires coupled to disordered superconductors
William S. Cole, Jay D. Sau, S. Das Sarma
DOI 10.1103/PhysRevB.94.140505 · Physical Review B
Active bibliographic source — not scientific approval
Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.
Abstract
We model a semiconductor wire with strong spin-orbit coupling which is proximity-coupled to a superconductor with chemical potential disorder. When tunneling at the semiconductor-superconductor interface is very weak, disorder in the superconductor does not affect the induced superconductivity nor, therefore, the effective topological superconductivity that emerges above a critical magnetic field. Here we demonstrate, nonperturbatively, how this result breaks down with stronger proximity coupling by obtaining the low-energy (i.e., subgap) excitation spectrum through direct numerical diagonalization of an appropriate Bogoliubov–de Gennes Hamiltonian. We find that the combination of strong proximity coupling and superconductor disorder suppresses the (nontopological) induced gap at zero magnetic field by disordering the induced pair potential. In the topological superconducting phase at large magnetic field, strong proximity coupling also reduces the localization length of Majorana bound states, such that the induced disorder eliminates the topological gap while bulk zero modes proliferate, even for short wires.
Similar papers
Soft superconducting gap in semiconductor-based Majorana nanowires
similarity 0.93Tudor D. Stanescu et al.
Source status unknown — claims are unverified
Density of states of disordered topological superconductor-semiconductor hybrid nanowires
similarity 0.93Jay D. Sau & S. Das Sarma
Source status unknown — claims are unverified
Exporting superconductivity across the gap: Proximity effect for semiconductor valence-band states due to contact with a simple-metal superconductor
similarity 0.92A. G. Moghaddam et al.
Source status unknown — claims are unverified
Majorana zero modes in semiconductor-superconductor hybrid structures: Defining topology in short and disordered nanowires through Majorana splitting
similarity 0.92Haining Pan & Sankar Das Sarma
Source status unknown — claims are unverified
Nonequilibrium charge dynamics in Majorana-Josephson devices
similarity 0.91Ian J. van Beek et al.
Source status unknown — claims are unverified
Robustness of Topological Superconductivity in Proximity-Coupled Topological Insulator Nanoribbons
similarity 0.91Piyapong Sitthison & Tudor D. Stanescu · 2014 · arXiv:1405.0328
Source status unknown — claims are unverified