Quantized conductance in semiconductor-superconductor-junction quantum point contacts

Yukihiko Takagaki; Hideaki Takayanagi

doi:10.1103/PhysRevB.53.14530

← Back to search

Quantized conductance in semiconductor-superconductor-junction quantum point contacts

Yukihiko Takagaki, Hideaki Takayanagi

DOI 10.1103/PhysRevB.53.14530 · Physical Review B

T1

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 present a numerical calculation of the quantized point contact conductance in a normal-metal-superconductor (NS) junction in the presence of disorder. It is shown that the flared geometry of the constriction improves the quantization. Random potential or interface roughness is found to destroy the quantization. The disorder induced suppression of the conductance is less significant when the constriction narrows due to retroreflection at the NS interface. The conductance approaches the value of normal point contacts when a magnetic field is applied. A good agreement of the magnetic-field dependence with an experiment is obtained.