AI Article Synopsis
- The study focuses on the chirality of massless fermions in Dirac semimetals, revealing its importance for understanding their behavior and potential applications.
- It shows that circularly polarized light can create an isospin polarization, which labels the chirality of these carriers, in the Dirac semimetal CdAs.
- The findings indicate a long scattering time and decay time for the isospin, suggesting that Dirac semimetals could have promising uses in future tech due to their robust and reversible properties.
Article Abstract
Chirality of massless fermions emerging in condensed matter is a key to understand their characteristic behavior as well as to exploit their functionality. However, the chiral nature of massless fermions in Dirac semimetals has remained elusive, due to equivalent occupation of carriers with the opposite chirality in thermal equilibrium. Here, we show that the isospin degree of freedom, which labels the chirality of massless carriers from a crystallographic point of view, can be injected by circularly polarized light. Terahertz Faraday rotation spectroscopy successfully detects the anomalous Hall conductivity by a light-induced isospin polarization in a three-dimensional Dirac semimetal, CdAs. Spectral analysis of the Hall conductivity reveals a long scattering time and a long decay time, which are characteristic of the isospin. The long-lived, robust, and reversible character of the isospin promises a potential application of Dirac semimetals in future information technology.
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| http://dx.doi.org/10.1021/acs.nanolett.3c03770 | DOI Listing |
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