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arXiv · 1612.08934

Photon-assisted transport in bilayer graphene flakes

D. Zambrano·L. Rosales·A. Latgé·M. Pacheco·P. A. Orellana
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Abstract

The electronic conductance of graphene-based bilayer flake systems reveal different quantum interference effects, such as Fabry-Pérot resonances and sharp Fano antiresonances on account of competing electronic paths through the device. These properties may be exploited to obtain spin-polarized currents when the same nanostructure is deposited above a ferromagnetic insulator. Here we study how the spin-dependent conductance is affected when a time-dependent gate potential is applied to the bilayer flake. Following a Tien-Gordon formalism we explore how to modulate the transport properties of such systems via appropriate choices of the $ac$-field gate parameters. The presence of the oscillating field opens the possibility of tuning the original antiresonances for a large set of field parameters. We show that interference patterns can be partially or fully removed by the time-dependent gate voltage. The results are reflected in the corresponding weighted spin polarization which can reach maximum values for a given spin component. We found that differential conductance maps as functions of bias and gate potentials show interference patterns for different $ac$-field parameter configurations. The proposed bilayer graphene flake systems may be used as a frequency detector in the THz range.

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D. Zambrano, L. Rosales, A. Latgé, M. Pacheco, P. A. Orellana. 2016-12-28. Photon-assisted transport in bilayer graphene flakes. https://doi.org/10.1103/physrevb.95.035412

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