Interaction phenomena in graphene seen through quantum capacitance
Abstract
Capacitance measurements provide a powerful means of probing the density of states. The technique has proved particularly successful in studying 2D electron systems, revealing a number of interesting many-body effects. Here, we use large-area high-quality graphene capacitors to study behavior of the density of states in this material in zero and high magnetic fields. Clear renormalization of the linear spectrum due to electron-electron interactions is observed in zero field. Quantizing fields lead to splitting of the spin- and valley-degenerate Landau levels into quartets separated by interaction-enhanced energy gaps. These many-body states exhibit negative compressibility but the compressibility returns to positive in ultrahigh B. The reentrant behavior is attributed to a competition between field-enhanced interactions and nascent fractional states.
Cite
@article{arxiv.1302.3967,
title = {Interaction phenomena in graphene seen through quantum capacitance},
author = {G. L. Yu and R. Jalil and Branson Belle and Alexander S. Mayorov and Peter Blake and Frederick Schedin and Sergey V. Morozov and Leonid A. Ponomarenko and F. Chiappini and S. Wiedmann and Uli Zeitler and Mikhail I. Katsnelson and A. K. Geim and Kostya S. Novoselov and Daniel C. Elias},
journal= {arXiv preprint arXiv:1302.3967},
year = {2013}
}