Strain Modulated Superlattices in Graphene

IMCN

Numerous theoretically proposed devices and novel phenomena have sought to take advantage of the intense pseudogauge fields that can arise in strained graphene. Many of these proposals, however, require fields to oscillate with a spatial frequency smaller than the magnetic length, while to date only the generation and effects of fields varying at a much larger length scale have been reported. Here, we describe the creation of short wavelength, periodic pseudogauge-fields using rippled graphene under extreme (>10%) strain and study of its effects on Dirac electrons.                         

Using first-principles and semi-empirical simulations, Dr. Viet-Hung Nguyen and Dr. Aurélien Lherbier in the group of J.-C. Charlier found that spatially oscillating strain generates a new quantization different from the familiar Landau quantization, as also measured by scanning tunneling microscopy in PennState. Indeed, graphene ripples cause large variations in carbon−carbon bond length, thus creating an effective electronic superlattice within a single graphene sheet. These results pave the way for a novel approach of synthesizing effective 2D lateral heterostructures by periodically modulating lattice strain.

Référence : R. Banerjee, V.-H. Nguyen, T. Granzier-Nakajima, L. Pabbi, A. Lherbier, A.R. Binion, J.-C. Charlier, M. Terrones, and E.W. Hudson, Nano Lett. 20, 3113-3121 (2020).

DOI.  10.1021/acs.nanolett.9b05108.

 

Published on May 15, 2020