Probing Fermi surface parity with spin resolved transverse magnetic focussing

TL;DR

This paper demonstrates that transverse magnetic focusing can detect parity changes in the Fermi surface of 2D systems, offering higher sensitivity than traditional methods and enabling new investigations into electronic properties.

Contribution

It introduces the use of transverse magnetic focusing as a sensitive method to probe Fermi surface parity changes in 2D materials, surpassing existing techniques.

Findings

Focusing measures specific Fermi surface sections without averaging over +k and -k.

Focusing is an order of magnitude more sensitive than other 2D techniques.

Potential to investigate Fermi surface parity changes in various 2D systems.

Abstract

Measurements of the Fermi surface are a fundamental technique for determining the electrical and magnetic properties of solids. In 2D systems, the area and diameter of the Fermi surface is typically measured using Shubnikov-de Haas oscillations and commensurability oscillations respectively. However, these techniques are unable to detect changes in the parity of the Fermi surface (i.e. when +k $\neq$ -k). Here, we show that transverse magnetic focussing can be used to detect such changes, because focussing only measures a well defined section of the Fermi surface and does not average over +k and -k. Furthermore, our results show that focussing is an order of magnitude more sensitive to changes in the Fermi surface than other 2D techniques, and could be used to investigate similar Fermi surface changes in other 2D systems.