The team of Professor Changying Zhao from Shanghai Jiaotong University revealed the asymmetric evolution mechanism of phase singularities in spectral space, and proposed a new method for nonreciprocal thermal radiation control

Recently, the team of Professor Changying Zhao from Shanghai Jiaotong University published a research paper "Evolution and nonreciprocity of loss-induced topological phase singularity pairs" in the international journal Physical Review Letters.

Kirchhoff’s law of thermal radiation states that the emissivity and absorptivity of a material under thermal equilibrium conditions are equal e(λ,θ)=α(λ,θ)

Figure 1 (Left picture) The generation mechanism of topological phase singularities; (Right picture) The relationship between the asymmetric evolutionary regulation of topological phase singularities in spectral space and system radiation loss

The research team used magneto-optical materials to systematically reveal material loss by studying the asymmetric characteristics of topological phase singularity pairs (TPSPs) split by bound states (BICs) in the continuum in the spectrum-parameter space.

Figure 2 Non-reciprocal thermal radiation control based on phase singularity of asymmetric topology

This kind of singularity appears at the position where the reflection intensity is 0.

This research applies asymmetric TPSPs to the design of non-reciprocal heat radiation devices, and provides a new method for theoretical and experimental research that breaks Kirchhoff's law

The research work has been funded by key projects of the National Natural Science Foundation of China, key international cooperation projects, and key basic research projects of Shanghai

Link to the paper : https://journals.