Effects of strain-tunable valleys on charge transport in bismuth

Abstract

The manipulation of the valley degree of freedom can boost the technological development of novel functional devices based on valleytronics. The current mainstream platform for valleytronics is to produce a monolayer with inversion asymmetry, in which the strain-band engineering through the substrates can serve to improve the performance of valley-based devices. However, pinpointing the effective role of strain is inevitable for the precise design of the desired valley structure. Here, we demonstrate the charge transport under continuously controllable external strain for bulk bismuth crystals with three equivalent electron valleys and one hole valley. The strain response of resistance, namely elastoresistance, exhibits the evolutions in both antisymmetric and symmetric channels with decreasing temperature. The elastoresistance behaviors mainly reflect the significant changes in valley density depending on the symmetry of induced strain, evidenced by our strain-dependent quantum oscillation measurements and first-principle band calculations under strain. These facts suggest the successful tune and evaluation of the valley populations through strain-dependent charge valley transport.

Main text: 13 pages with 7 figures, DFT calculation results are added

References in corpus (10)

• Valley polarization in MoS2 monolayers by optical pumping
• Substrate-induced band gap opening in epitaxial graphene
• Valley susceptibility of an interacting two-dimensional electron system
• Transport Properties and Diamagnetism of Dirac Electrons in Bismuth
• Observation of a Nematic Quantum Hall Liquid on the Surface of Bismuth
• Electronic phase transitions of bismuth under strain from relativistic self-consistent GW calculations
• Angle dependence of the orbital magnetoresistance in bismuth
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• Pure nematic quantum critical point accompanied by a superconducting dome
• Boundary conductance in macroscopic bismuth crystals

Cited by in corpus (2)

• Development of microwave surface elastoresistivity measurement technique under tunable strain
• Valley polarization of Landau levels driven by residual strain in the ZrSiS surface band