How to detect a genuine quantum pump effect in graphene?

Abstract

Quantum pumping in graphene has been predicted in recent years. Till date there have been no experiments indicating a graphene based quantum pump. This is not uncommon as in the case of other non-Dirac behavior showing materials it has not yet been unambiguously experimentally detected. The reason is that in experiments with such materials the rectification effect overshadows the pumped current. In this work we answer the question posed in the title by taking recourse to “strain.” We show that the symmetries of the rectified and pumped currents towards strain reversal can effectively distinguish between the two.