Competition between electronic cooling and Andreev dissipation in a superconducting micro-cooler

Sukumar Rajauria (1) , Philippe Gandit (2) , Frank. W. J. Hekking (3) , Bernard Pannetier (1) , Hervé Courtois (4)

1 NEEL - Institut Néel
2 NEEL - HELFA - Hélium : du fondamental aux applications
3 LPM2C - Laboratoire de physique et modélisation des milieux condensés
4 CP

We discuss very low temperature experiments on superconducting micro-coolers made of a double Normal metal - Insulator - Superconductor junction. We investigate with a high resolution the differential conductance of the micro-cooler as well as of additional probe junctions. There is an explicit crossover between the single quasi-particle current and the phase-coherent Andreev current. We establish a thermal model by considering the thermal contribution due to the Andreev current. The related increase of the electron temperature is discussed, including the influence of several parameters like the phase-coherence length or the tunnel junction transparency.

Domaines: Supraconductivité [cond-mat.supr-con]

Sukumar Rajauria, Philippe Gandit, Frank. W. J. Hekking, Bernard Pannetier, Hervé Courtois. Competition between electronic cooling and Andreev dissipation in a superconducting micro-cooler. 2008. ⟨hal-00332877v1⟩