Evidence for an excited nonequilibrium quasiparticle distribution in superconducting tunnel junctions resulting from energy accumulation via sequential tunneling
A. G. Kozorezov, J. K. Wigmore, A. Peacock, R. den Hartog, D. Martin, G. Brammertz, P. Verhoeve, N. Rando
DOI 10.1103/PhysRevB.69.184506 · 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 have observed experimentally and modeled theoretically a previously unidentified nonequilibrium state in superconducting tunnel junctions. The state occurs in small gap, multiple tunneling junctions, and is caused by the raising in energy of the quasiparticle distribution through multiple cycles of sequential forward- and back-tunneling events. Because of the low-energy gap, quasiparticles may survive in the higher-energy states until they reach the energy threshold for emission of Cooper pair-breaking phonons, leading to generation of further quasiparticles. We modeled the process by solving the coupled system of kinetic equations for interacting quasiparticles and phonons, and studied the effect experimentally in high quality Al and Ta/Al superconducting tunnel junctions in the temperature range 40–300 mK. The distinctive features are large subgap currents exceeding that due to thermal excitations by several orders of magnitude at low temperatures, together with a very sharp onset of current with bias voltage.
Source-reported materials — not catalogue approval
| Formula | Reported Tc (K) | Pressure (GPa) | Type |
|---|---|---|---|
| Al Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | — | Pressure not reported | unknown |
| Ta/Al Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | — | Pressure not reported | unknown |
| Nb Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | — | Pressure not reported | unknown |
| Ta Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | — | Pressure not reported | unknown |
| Nb/Al Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | — | Pressure not reported | unknown |
Similar papers
Quasiparticle number fluctuations in superconductors
similarity 0.96C. M. Wilson & D. E. Prober
Source status unknown — claims are unverified
Superconductive fluctuations in the density of states and tunneling resistance in high-Tc superconductors
similarity 0.95C. Di Castro et al.
Source status unknown — claims are unverified
Dynamical quantum phase transitions in a mesoscopic superconducting system
similarity 0.95K. Wrześniewski et al.
Source status unknown — claims are unverified
Characterization of collective excitations in weakly coupled disordered superconductors
similarity 0.95Bo Fan et al.
Source status unknown — claims are unverified
Dynamics and energy distribution of nonequilibrium quasiparticles in superconducting tunnel junctions
similarity 0.95K. Segall et al.
Source status unknown — claims are unverified
Heating of quasiparticles driven by oscillations of the order parameter in short superconducting microbridges
similarity 0.95D. Y. Vodolazov & F. M. Peeters
Source status unknown — claims are unverified