|Instituto de Ciencia de Materiales de Madrid|
|Condensed Matter Theory|
|Sigmund Kohler||home | cv | research | publications|
Single-parameter pumping in graphenePablo San-Jose, Elsa Prada, Sigmund Kohler, and Henning Schomerus
Phys. Rev. B 84, 155408 (2011)
We propose a quantum pump mechanism based on the particular properties of graphene, namely chirality and bipolarity. The underlying physics is the excitation of evanescent modes entering a potential barrier from one lead, while those from the other lead do not reach the driving region. This induces a large nonequilibrium current with electrons stemming from a broad range of energies, in contrast to the narrow resonances that govern the corresponding effect in semiconductor heterostructures. Moreover, the pump mechanism in graphene turns out to be robust, with a simple parameter dependence, which is beneficial for applications. Numerical results from a Floquet scattering formalism are complemented with analytical solutions for small to moderate driving.
[Condensed Matter Theory]
last modified: 18.6.2018 by Sigmund Kohler