Using coherent phonons for ultrafast control of the Dirac node of SrMnSb₂

Authors

Christopher P. Weber, Santa Clara UniversityFollow
Madison G. Masten
Thomas C. Ogloza
Bryan S. Berggren
Michael K. L. Man
Keshav M. Dani
Jinyu Liu
Zhiqiang Mao
Dennis D. Klug
Adebayo A. Adeleke
Yansun Yao

Document Type

Article

Publication Date

10-8-2018

Publisher

American Physical Society

Abstract

SrMnSb₂ is a candidate Dirac semimetal whose electrons near the Y point have the linear dispersion and low mass of a Dirac cone. Here we demonstrate that ultrafast, 800-nm optical pulses can launch coherent phonon oscillations in Sr_0.94Mn_0.92Sb₂, particularly an A_g mode at 4.4 THz. Through first-principles calculations of the electronic and phononic structure of SrMnSb₂, we show that high-amplitude oscillations of this mode would displace the atoms in a way that transiently opens and closes a gap at the node of the Dirac cone. The ability to control the nodal gap on a subpicosecond timescale could create opportunities for the design and manipulation of Dirac fermions.

Comments

Copyright © 2018 American Physical Society. Reprinted with permission.

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Recommended Citation

C. P. Weber, M. G. Masten, T. C. Ogloza, B. S. Berggren, M. K. L. Man, K. M. Dani, J. Liu, Z. Mao, D. D. Klug, A. A. Adeleke, and Y. Yao, “Using coherent phonons for ultrafast control of the Dirac node of SrMnSb₂”, Phys. Rev. B 98 155115 (2018). https://journals.aps.org/prb/ abstract/10.1103/PhysRevB.98.155115