Levitons in superconducting point contacts

Matteo Acciai (1) , Flavio Ronetti , Dario Ferraro (2) , Jérôme Rech (3, 4) , Thibaut Jonckheere (3, 4) , Maura Sassetti (1) , Thierry Martin (3, 4)

1 UniGe - Università degli studi di Genova = University of Genoa
2 Departement de Physique Théorique [Genève]
3 CPT - Centre de Physique Théorique - UMR 7332
4 CPT - E6 Nanophysique

We investigate the transport properties of a superconducting quantum point contact in the presence of an arbitrary periodic drive. In particular, we calculate the DC current and noise in the tunnel limit, obtaining general expressions in terms of photoassisted probabilities. Interesting features can be observed when the frequency is comparable to the gap. Here, we show that quantized Lorentzian pulses minimize the excess noise, further strengthening the hierarchy among different periodic drives observed in the electron quantum optics domain. In this regime, the excess noise is directly connected to the overlap between electron and hole energy distributions driven out of equilibrium by the applied voltage. In the adiabatic limit, where the frequency of the drive is very small compared to the superconducting gap, we recover the conventional Shapiro-spikes physics in the supercurrent.

Domaines: Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]; Supraconductivité [cond-mat.supr-con]

Matteo Acciai, Flavio Ronetti, Dario Ferraro, Jérôme Rech, Thibaut Jonckheere, et al.. Levitons in superconducting point contacts. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2019, 100 (8), pp.085418. ⟨10.1103/PhysRevB.100.085418⟩. ⟨hal-02360242⟩