We study inelastic energy relaxation in graphene for low energies to find out how electrons scatter with acoustic phonons and other electrons. By coupling the graphene to superconductors, we create a strong dependence of the measured signal, i.e.,\ critical Josephson current, on the electron population on different energy states. Since the relative population of high- and low-energy states is determined by the inelastic scattering processes, the critical current becomes an effective probe for their strength. We argue that the electron-electron interaction is the dominant relaxation method and, in our model of two-dimensional electron-electron scattering, we find a scattering time τe−e=5...13 ps at T=500 mK, 1-2 orders of magnitude smaller than predicted by theory.
@article{arxiv.1103.3234,
title = {Energy relaxation in graphene and its measurement with supercurrent},
author = {Juha Voutilainen and Aurelien Fay and Pasi Häkkinen and Janne K. Viljas and Tero T. Heikkilä and Pertti J. Hakonen},
journal= {arXiv preprint arXiv:1103.3234},
year = {2015}
}
Comments
10 pages, 13 figures submitted to Physical Review B