Magnetic-field-tunable anisotropic blackbody radiation and condensation of slow thermal light in dynamical axion insulators

TL;DR

This paper explores how magnetic fields influence anisotropic blackbody radiation in dynamical axion insulators, revealing a phase with slow thermal photons and potential for directional thermal control.

Contribution

It demonstrates magnetic-field-tunable anisotropic blackbody radiation and identifies a slow thermal photon phase in dynamical axion insulators, advancing thermal quantum manipulation.

Findings

Radiation becomes highly anisotropic due to strong dispersion.

A low-temperature phase with slow thermal photons is identified.

Heat radiation asymmetry can be controlled magnetically.

Abstract

Thermal radiation features of dynamical axion insulators, which are characterized by an antiferromagnetic order with simultaneously broken time-reversal and space-inversion symmetries, are investigated. Planck's radiation law is shown to exhibit remarkable anisotropic behavior as a result of the strong dispersion caused by the light-matter interaction. A crossover scenario at low temperature is identified and an associated phase highly populated by slow thermal photons is revealed. We show that the asymmetry degree of the heat radiation and its angular distribution can be controlled via a magnetic field, paving the way toward a directional-tunable mechanism for thermal quantum manipulation and storage. Analogies are drawn with the expected behavior of blackbody radiation in the core of neutron stars.