Engineering Topology in Massive Dirac Fermions
ORAL
Abstract
We engineer topology in massive Dirac fermions in transition-metal dichalcogenide (TMD) monolayer and bilayer materials using an artificial superlattice potential that can be created with contemporary experimental techniques such as with LaAlO$_3$/SrTiO$_3$ interface. We use symmetry analysis to analyze band inversions to provide the Chern number $mathcal C$ for the valence band as a function of tunable potential parameter space for a class of $C_4$ and $C_3$ symmetric potentials. We present a novel method to engineer Chern number $mathcal C=2$ for the valence band and show that the applied potential must have a scalar together with a non-scalar periodic part. We discover that externally applied potential allows the possibility of non-trivial topological transitions that cannot be achieved by naturally occurring moir'e patterns produced by a twist or lattice mismatch. We finally discuss the experimental implementation of our work which allows for the possibility to realize the quantum Spin Hall effect (QSHE), quantum Hall effect (QHE), and even exotic non-Abelian anyons in the fractional quantum Hall effect (FQHE).
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Presenters
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Nishchay Suri
NASA Ames Research Center
Authors
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Nishchay Suri
NASA Ames Research Center
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Chong Wang
University of Washington, Carnegie Mellon University
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Benjamin M Hunt
Carnegie Mellon University
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Di Xiao
University of Washington, 1. Department of Materials Science & Engineering, University of Washington, Seattle WA 98915 2. Department of Physics, University of Washington, Seattle WA 98915, Department of Materials Science & Engineering, Department of Physics, University of Washington; Pacific Northwest National Laboratory