Formation of artificial Fermi surfaces with a triangular superlattice on a conventional two dimensional electron gas

Fuente: arXiv
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Main Authors: Wang, Daisy Q., Krix, Zeb, Sushkov, Oleg P., Farrer, Ian, Ritchie, David A., Hamilton, Alexander R., Klochan, Oleh
Format: Preprint
Published: 2024
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author Wang, Daisy Q.
Krix, Zeb
Sushkov, Oleg P.
Farrer, Ian
Ritchie, David A.
Hamilton, Alexander R.
Klochan, Oleh
author_facet Wang, Daisy Q.
Krix, Zeb
Sushkov, Oleg P.
Farrer, Ian
Ritchie, David A.
Hamilton, Alexander R.
Klochan, Oleh
contents In nearly free electron theory the imposition of a periodic electrostatic potential on free electrons creates the bandstructure of a material, determined by the crystal lattice spacing and geometry. Imposing an artificially designed potential to the electrons confined in a GaAs quantum well makes it possible to engineer synthetic two-dimensional band structures, with electronic properties different from those in the host semiconductor. Here we report the fabrication and study of a tuneable triangular artificial lattice on a GaAs/AlGaAs heterostructure where it is possible to transform from the original GaAs bandstructure and Fermi surface to a new bandstructure with multiple artificial Fermi surfaces simply by altering a gate bias. For weak electrostatic potential modulation magnetotransport measurements reveal quantum oscillations from the GaAs two-dimensional Fermi surface, and classical oscillations due to these electrons scattering from the artificial lattice. Increasing the strength of the modulation reveals new quantum oscillations due to the formation of multiple artificial Fermi surfaces, and ultimately to new classical oscillations of the electrons from the artificial Fermi surface scattering from the superlattice modulation. These results show that low disorder gate-tuneable lateral superlattices can be used to form artificial two dimensional crystals with designer electronic properties.
format Preprint
id arxiv_https___arxiv_org_abs_2403_06426
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Formation of artificial Fermi surfaces with a triangular superlattice on a conventional two dimensional electron gas
Wang, Daisy Q.
Krix, Zeb
Sushkov, Oleg P.
Farrer, Ian
Ritchie, David A.
Hamilton, Alexander R.
Klochan, Oleh
Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
In nearly free electron theory the imposition of a periodic electrostatic potential on free electrons creates the bandstructure of a material, determined by the crystal lattice spacing and geometry. Imposing an artificially designed potential to the electrons confined in a GaAs quantum well makes it possible to engineer synthetic two-dimensional band structures, with electronic properties different from those in the host semiconductor. Here we report the fabrication and study of a tuneable triangular artificial lattice on a GaAs/AlGaAs heterostructure where it is possible to transform from the original GaAs bandstructure and Fermi surface to a new bandstructure with multiple artificial Fermi surfaces simply by altering a gate bias. For weak electrostatic potential modulation magnetotransport measurements reveal quantum oscillations from the GaAs two-dimensional Fermi surface, and classical oscillations due to these electrons scattering from the artificial lattice. Increasing the strength of the modulation reveals new quantum oscillations due to the formation of multiple artificial Fermi surfaces, and ultimately to new classical oscillations of the electrons from the artificial Fermi surface scattering from the superlattice modulation. These results show that low disorder gate-tuneable lateral superlattices can be used to form artificial two dimensional crystals with designer electronic properties.
title Formation of artificial Fermi surfaces with a triangular superlattice on a conventional two dimensional electron gas
topic Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
url https://arxiv.org/abs/2403.06426