English

Chiralometer: Direct Torque Detection of Crystal Chirality

Materials Science 2026-02-11 v1 Other Condensed Matter

Abstract

Chirality governs phenomena ranging from chemical reactions to the topology of quasiparticle charge carriers. However, a direct macroscopic probe for crystal chirality remains a significant challenge, especially in time reversal symmetric systems with weak circular dichroism signal. Here, we propose the ``Chiralometer'', a mechanical detection method that probes chirality by driving angular momentum carriers out of equilibrium. Using first-principles calculations and semiclassical transport theory, we demonstrate that a temperature gradient in insulators or an electric field in metals induces uncompensated angular momentum in phonons and electrons, respectively. This imbalance generates a macroscopic mechanical torque (τ1011Nm\tau \sim 10^{-11} N \cdot m) well within the sensitivity of modern torque magnetometry and cantilever-based sensors. We identify robust signatures in chiral crystals such as Te, SiO2_2, and the topological semimetal CoSi. Our work establishes mechanical torque as a fundamental order parameter for chirality, offering a transformative tool for orbitronics and chiral quantum materials.

Keywords

Cite

@article{arxiv.2602.09556,
  title  = {Chiralometer: Direct Torque Detection of Crystal Chirality},
  author = {Nikolai Peshcherenko and Ning Mao and Claudia Felser and Yang Zhang},
  journal= {arXiv preprint arXiv:2602.09556},
  year   = {2026}
}
R2 v1 2026-07-01T10:29:22.452Z