Unconventional Thermophotonic Charge Density Wave

TL;DR

This paper uncovers an unconventional thermophotonic effect in charge density wave material TiSe2, revealing negative temperature dependence in thermal photon transport due to interplay of plasmon polaritons and CDW excitations, with implications for heat flow control.

Contribution

It introduces the concept of thermophotonic-CDW ($tp$-CDW) and demonstrates its unique thermal transport properties through combined theoretical approaches.

Findings

Negative temperature dependence in thermal photon transport.

Interplay of plasmon polaritons and CDW excitations causes anomalous effects.

Potential for controllable heat flow manipulation in energy devices.

Abstract

Charge-order states of broken symmetry, such as charge density wave (CDW), are able to induce exceptional physical properties, however, the precise understanding of the underlying physics is still elusive. Here, we combine fluctuational electrodynamics and density functional theory to reveal an unconventional thermophotonic effect in CDW-bearing TiSe$_2$, referred to as thermophotonic-CDW ($tp$-CDW). The interplay of plasmon polariton and CDW electron excitations give rise to an anomalous negative temperature dependency in thermal photons transport, offering an intuitive fingerprint for a transformation of the electron order. Additionally, the demonstrated nontrivial features of $tp$-CDW transition hold promise for a controllable manipulation of heat flow, which could be extensively utilized in various fields such as thermal science and electron dynamics, as well as in next-generation energy devices.