English

Anomalous circular phonon dichroism in transition metal dichalcogenides

Mesoscale and Nanoscale Physics 2023-01-04 v1

Abstract

A magnetic field can generally induce circular phonon dichroism based on the formation of Landau levels of electrons. Here, we study the magnetization-induced circular phonon dichroism in transition metal dichalcogenides, without forming Landau levels. We find that, instead of the conventional deformation potential coupling, pseudogauge-type electron-phonon coupling plays an essential role in the emergence of the phenomenon. As a concrete example, a large dichroism signal is obtained in monolayer MoTe2 on a EuO substrate, even without considering Rashba spin-orbit coupling. Due to the two-dimensional spin-valley-coupled band structure, MoTe2 shows a reciprocal and nonreciprocal absorption of circularly polarized acoustic phonons upon reversing the direction of phonon propagation and magnetization, respectively. By varying the gate voltage, a tunable circular phonon dichroism can be realized, which paves a way toward different physics and applications of two-dimensional acoustoelectronics.

Keywords

Cite

@article{arxiv.2301.00917,
  title  = {Anomalous circular phonon dichroism in transition metal dichalcogenides},
  author = {Wen-Yu Shan},
  journal= {arXiv preprint arXiv:2301.00917},
  year   = {2023}
}

Comments

6 pages,3 figures