Bandyopadhyay, A and Joseph, NB and Narayan, A (2022) Electrically switchable giant Berry curvature dipole in silicene, germanene and stanene. In: 2D Materials, 9 (3).
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Abstract
The anomalous Hall effect in time-reversal symmetry broken systems is underpinned by the concept of Berry curvature in band theory. However, recent experiments reveal that the nonlinear Hall effect (NHE) can be observed in non-magnetic systems without applying an external magnetic field. The emergence of NHE under time-reversal symmetric conditions can be explained in terms of non-vanishing Berry curvature dipole (BCD) arising from inversion symmetry breaking. In this work, we availed realistic tight-binding models, first-principles calculations, and symmetry analyses to explore the combined effect of transverse electric field and strain, which leads to a giant BCD in the elemental buckled honeycomb lattices—silicene, germanene, and stanene. The external electric field breaks the inversion symmetry of these systems, while strain helps to attain an asymmetrical distribution of Berry curvature of a single valley. Furthermore, the topology of the electronic wavefunction switches from the band inverted quantum spin Hall state to normal insulating one at the gapless point. This band gap closing at the critical electric field strength is accompanied by an enhanced Berry curvature and concomitantly a giant BCD at the Fermi level. Our results predict the occurrence of an electrically switchable nonlinear electrical and thermal Hall effect in a new class of elemental systems that can be experimentally verified.
| Item Type: | Journal Article |
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| Publication: | 2D Materials |
| Publisher: | Institute of Physics |
| Additional Information: | The copyright for this article belongs to the Author(s). |
| Keywords: | Calculations; Electric fields; Electric switches; Energy gap; Honeycomb structures; Quantum Hall effect; Quantum theory; Silicene; Spin Hall effect; Topology, Berry curvature; Berry curvature dipole; Germanene; Inversion symmetry; Non linear; Non-linear hall effect; Silicene; Stanene; Switchable; Two-dimensional materials, Fruits |
| Department/Centre: | Division of Chemical Sciences > Solid State & Structural Chemistry Unit |
| Date Deposited: | 19 Sep 2022 10:10 |
| Last Modified: | 19 Sep 2022 10:10 |
| URI: | https://eprints.iisc.ac.in/id/eprint/76608 |
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