https://doi.org/10.1140/epjb/e2014-50254-6
Regular Article
Transport properties of overheated electrons trapped on a helium surface
1 Laboratoire de Physico-Chimie Théorique, UMR CNRS Gulliver 7083, ESPCI, 75005 Paris, France
2 Laboratoire de Physique Théorique de la Matière Condensée, UMR 7600 LPTMC, 4 place Jussieu, 75252 Paris Cedex 05, France
3 Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 OHE, UK
a
e-mail: alexei.chepelianskii@gmail.com
Received: 16 April 2014
Received in final form: 6 June 2014
Published online: 11 August 2014
An ultra-strong photovoltaic effect has recently been reported for electrons trapped on a liquid helium surface under a microwave excitation tuned at intersubband resonance [D. Konstantinov, A.D. Chepelianskii, K. Kono, J. Phys. Soc. Jpn 81, 093601 (2012)]. In this article, we analyze theoretically the redistribution of the electron density induced by an overheating of the surface electrons under irradiation, and obtain quantitative predictions for the photocurrent dependence on the effective electron temperature and confinement voltages. We show that the photo-current can change sign as a function of the parameters of the electrostatic confinement potential on the surface, while the photocurrent measurements reported so far have been performed only at a fixed confinement potential. The experimental observation of this sign reversal could provide a reliable estimation of the electron effective temperature in this new out of equilibrium state. Finally, we have also considered the effect of the temperature on the outcome of capacitive transport measurement techniques. These investigations led us to develop, numerical and analytical methods for solving the Poisson-Boltzmann equation in the limit of very low temperatures which could be useful for other systems.
Key words: Statistical and Nonlinear Physics
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2014
