nl9b05108_si_001.pdf (1.01 MB)
Strain Modulated Superlattices in Graphene
journal contribution
posted on 2020-03-10, 20:13 authored by Riju Banerjee, Viet-Hung Nguyen, Tomotaroh Granzier-Nakajima, Lavish Pabbi, Aurelien Lherbier, Anna Ruth Binion, Jean-Christophe Charlier, Mauricio Terrones, Eric William HudsonNumerous 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. Combining scanning tunneling microscopy and atomistic
calculations, we find that spatially oscillating strain generates
a new quantization different from the familiar Landau quantization.
Graphene ripples also cause large variations in carbon–carbon
bond length, creating an effective electronic superlattice within
a single graphene sheet. Our results thus also establish a novel approach
of synthesizing effective 2D lateral heterostructures by periodically
modulating lattice strain.