Excitation of single quasiparticles in a small superconducting Al island connected to normal-metal leads by tunnel junctions

V.F. Maisi (Corresponding Author), S.V. Lotkhov, Antti Kemppinen, A. Heimes, J.T. Muhonen, J.P. Pekola

Research output: Contribution to journalArticleScientificpeer-review

30 Citations (Scopus)

Abstract

We investigate the dynamics of individual quasiparticle excitations on a small superconducting aluminum island connected to normal metallic leads by tunnel junctions. We find the island to be free of excitations within the measurement resolution. This allows us to show that the residual heating, which typically limits experiments on superconductors, has an ultralow value of less than 0.1 aW. By injecting electrons with a periodic gate voltage, we probe electron-phonon interaction and relaxation down to a single quasiparticle excitation pair, with a measured recombination rate of 16 kHz. Our experiment yields a strong test of BCS theory in aluminum as the results are consistent with it without free parameters.
Original languageEnglish
Article number147001
JournalPhysical Review Letters
Volume111
Issue number14
DOIs
Publication statusPublished - 2013
MoE publication typeA1 Journal article-refereed

Fingerprint Dive into the research topics of 'Excitation of single quasiparticles in a small superconducting Al island connected to normal-metal leads by tunnel junctions'. Together they form a unique fingerprint.

  • Cite this