Quantum spin Hall effect in metamaterials

Abstract

Quantum spin Hall effect (QSHE) of electrons has improved the development of condensed matter researchnowadays, which describesone kind of spin-dependent quantum transport behavior in solid state. Recently, a variety of theoretical and experimental work has revealed that Maxwell equations, which is formulated 150 years ago and ultimately describeproperties of light, can exhibit an intrinsic quantum spin Hall effect of light. The evanescent wave supported on the interface among different media behaves strong spin-momentum locking. With the rapid development of new optics materials, metamaterials, we can not only adjust the optical parameters of media arbitrarily, but also introduce a lot of complex spin-orbit interaction mechanism. Based on metamaterials, the essential physical mechanism behind quantum spin Hall effect of light can be understood deeply and verified easily. The purpose of this review is to give a brief introduction to quantum spin Hall effect of light in metamaterials. These include, for example, the physical essence of QSHE of light, the topological interface mode between permittivity negative and permeability negative metamaterials, QSHE in topological circuits.