Staggered Pseudo Magnetic Field in Twisted Transition Metal Dichalcogenides: Physical Origin and Experimental Consequences

TL;DR

This paper demonstrates that twisted bilayer WSe2 creates a tunable staggered magnetic flux affecting electronic properties, leading to observable effects like Hall coefficient sign reversal and edge spin currents.

Contribution

It reveals that twisted transition metal dichalcogenide bilayers can host a strong, tunable staggered flux, providing new insights into their quantum physics and potential experimental signatures.

Findings

Staggered flux arises in twisted WSe2 bilayers.

Sign reversal of Hall coefficient under interlayer potential.

Emergence of spin currents at edges and interfaces.

Abstract

Strong magnetic fields profoundly affect the quantum physics of charged particles, as seen for example by the integer and fractionally quantized Hall effects, and the fractal `Hofstadter butterfly' spectrum of electrons in the presence of a periodic potential and a magnetic field. Intrinsic physics can lead to effects equivalent to those produced by an externally applied magnetic field. Examples include the `staggered flux' phases emerging in some theories of quantum spin liquids and the Chern insulator behavior of twisted bilayer graphene when valley symmetry is broken. In this paper we show that when two layers of the transition metal dichalcogenide material WSe2 are stacked at a small relative twist angle to form a Moire bilayer, the resulting low energy physics can be understood in terms of electrons moving in a strong and tunable staggered flux. We predict experimental consequences including sign reversals of the Hall coefficient on application of an interlayer potential and spin currents appearing at sample edges and interfaces.