Fizika Nizkikh Temperatur: Volume 48, Number 6 (June 2022), p. 535-541    ( to contents , go back )

Cooling of nanomechanical vibrations by Andreev injection

O. M. Bahrova1,2, S. I. Kulinich2, L. Y. Gorelik3, R. I. Shekhter4, and H. C. Park1

1Center for Theoretical Physics of Complex Systems, Institute for Basic Science, Daejeon 34126, Republic of Korea

2B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine Kharkiv 61103, Ukraine

3Department of Physics, Chalmers University of Technology, Göteborg SE-412 96, Sweden
4Department of Physics, University of Gothenburg, Göteborg SE-412 96, Sweden
E-mail: olha.bahrova@gmail.com, kulinich @ilt.kharkov.ua
pos Анотація:930

Received February 14, 2022, published online April 25, 2022

Abstract

A nanoelectromechanical weak link composed of a carbon nanotube suspended between two normal electrodes in a gap between two superconducting leads is considered. The nanotube is treated as a movable single-level quantum dot in which the position-dependent superconducting order parameter is induced due to the Cooper pair tunneling. We show that electron tunneling processes significantly affect the state of the mechanical subsystem. We found that at a given direction of the applied voltage between the electrodes, the stationary state of the mechanical subsystem has a Boltzmann form with an effective temperature depended on the parameters of the device. As this takes place, the effective temperature can reach significantly small values (cooling effect). We also demonstrate that nanotube fluctuations strongly affect the dc current through the system. The latter can be used to probe the predicted effects in an experiment.

Key words: nanoelectromechanical system, Andreev reflection, quantum dot.

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