Weak-value amplification for Weyl-point separation in momentum space

Abstract

The existence of Weyl nodes in the momentum space is a hallmark of a Weyl semimetal (WSM). A WSM can be confirmed by observing its Fermi arcs with separated Weyl nodes. In this paper, we study the spin–orbit interaction of light on the surface of a WSM thin film. Our results show that the spin-dependent splitting induced by the spin–orbit interaction is related to the separation of Weyl nodes. By proposing an amplification technique called weak measurements, the distance of the nodes can be precisely determined. This system may have an application in characterizing other parameters of WSM.

Keywords

• photonic spin Hall effect
• weak measurements
• spin–orbit coupling