Supergap anomalies in cotunneling between normal-superconducting and between two superconducting leads via a small quantum dot
V. V. Mkhitaryan, M. E. Raikh
DOI 10.1103/PhysRevB.77.195329 · 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
Cotunneling current through a resonant level coupled to either normal and superconducting or to two superconducting leads is studied for the domain of bias voltages V, exceeding the superconducting gap 2Δ. Due to the on-site repulsion in the resonant level, cotunneling of an electron is accompanied by the creation of a quasiparticle in a superconducting lead. Energy conservation imposes a threshold for this inelastic transport channel: Vc=3Δ for normal-superconductor case and Ṽc=4Δ for the superconductor-superconductor (S-S) case. We demonstrate that the behavior of the current near the respective thresholds is nonanalytic, namely, δIin(V)∝(V−Vc)3/2Θ(V−Vc) and δIin(V)∝(V−Ṽc)Θ(V−Ṽc). Stronger anomaly for the S-S leads is the consequence of the enhanced density of states at the edges of the gap. In addition, the enhanced density of states makes the threshold anomalies for two-electron cotunneling processes in the Coulomb-blockaded regions more pronounced than for the normal-normal leads.
Similar papers
Supergap anomalies in cotunneling between N-S and between S-S leads via a small quantum dot
similarity 0.92V. V. Mkhitaryan & M. E. Raikh · 2008 · arXiv:0802.0586
Source status unknown — claims are unverified
dc Josephson current through a quantum dot coupled with superconducting leads
similarity 0.89Satoshi Ishizaka et al.
Source status unknown — claims are unverified
Subgap features due to quasiparticle tunneling in quantum dots coupled to superconducting leads
similarity 0.89Sebastian Pfaller et al. · 2012 · arXiv:1208.6168
Source status unknown — claims are unverified