Antichiral Spin Order, its Soft Modes, and their Hybridization with Phonons in the Topological Semimetal Mn3Ge

Published

August 3, 2020

Author(s)

Y. Chen, Jonathan Gaudet, S. Dasgupta, G. G. Marcus, J. Lin, T. Chen, T. Tomita, M. Ikhlas, Yang Zhao, Wangchun Chen, Matthew B. Stone, O. Tchernyshyov, S. Nakatsuji, Collin L. Broholm

Abstract

Quantum materials with strong transport responses to disparate physical quantities are of great fundamental significance and may hold technological potentials. The interplay between interactions and topology drive such responses through the effects of spontaneous symmetry breaking and the associated domain configurations on quantum transport. Here we provide a comprehensive description of the magnetism of Mn₃Ge, an antiferromagnetic kagome-based semimetal with room temperature transport anomalies associated with topologically protected Weyl nodes. Using polarized neutron diffraction, we show the all-important magnetic structure is anti-chiral and coplanar carrying the symmetry of a ferromagnet without appreciable magnetization. We probe and classify the long wavelength excitations that determine its macroscopic responses including a set of collective magneto-elastic modes. We develop a phenomenological spin Hamiltonian with exchange, Dzyaloshinskii-Moriya, and crystal field interactions to describe its collective magnetism. The itinerant character of the magnetism that drives quantum transport is apparent in spin wave damping and extended magnetic interactions. Our work provides the scientific basis for manipulation of the chiral antiferromagnetic texture of Mn₃Ge to control its topological quantum transport.

Citation

Physical Review B

Volume

105

Issue

5

Pub Type

Journals

Citation

Chen, Y. , Gaudet, J. , Dasgupta, S. , Marcus, G. , Lin, J. , Chen, T. , Tomita, T. , Ikhlas, M. , Zhao, Y. , Chen, W. , Stone, M. , Tchernyshyov, O. , Nakatsuji, S. and Broholm, C. (2020), Antichiral Spin Order, its Soft Modes, and their Hybridization with Phonons in the Topological Semimetal Mn₃Ge, Physical Review B (Accessed May 10, 2024)