Pressure-induced ferromagnetism in the topological semimetal EuCd2As2
Date
2021-10-13
Authors
Gati, Elean
Bud'ko, Sergey L.
Wang, Lin-Lin
Valadkhani, Adrian
Gupta, Ritu
Kuthanazhi, Brinda
Xiang, Li
Wilde, John M.
Sapkota, Aashish
Guguchia, Zurab
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Iowa State University Digital Repository, Ames IA (United States)
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Physics and AstronomyAmes Laboratory
Abstract
The antiferromagnet and semimetal EuCd2As2 has recently attracted a lot of attention due to a wealth of
topological phases arising from the interplay of topology and magnetism. In particular, the presence of a single
pair of Weyl points is predicted for a ferromagnetic configuration of Eu spins along the c axis in EuCd2As2.
In the search for such phases, we investigate here the effects of hydrostatic pressure in EuCd2As2. For that, we
present specific heat, transport, and μSR measurements under hydrostatic pressure up to ∼2.5 GPa, combined
with ab initio density functional theory (DFT) calculations. Experimentally, we establish that the ground state of
EuCd2As2 changes from in-plane antiferromagnetic (AFMab) to ferromagnetic at a critical pressure of ≈2 GPa,
which is likely characterized by the moments dominantly lying within the ab plane (FMab). The AFMab-FMab
transition at such a relatively low pressure is supported by our DFT calculations. Furthermore, our theoretical
results indicate that EuCd2As2 moves closer to the sought-for FMc state (moments c) with increasing pressure
further. We predict that a pressure of ≈23 GPa will stabilize the FMc state if Eu remains in a 2+ valence state.
Thus, our work establishes hydrostatic pressure as a key tuning parameter that (i) allows for a continuous tuning
between magnetic ground states in a single sample of EuCd2As2 and (ii) enables the exploration of the interplay
between magnetism and topology and thereby motivates a series of future experiments on this magnetic Weyl
semimetal.
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This article is published as Gati, Elena, Sergey L. Bud'ko, Lin-Lin Wang, Adrian Valadkhani, Ritu Gupta, Brinda Kuthanazhi, Li Xiang et al. "Pressure-induced ferromagnetism in the topological semimetal Eu Cd 2 As 2." Physical Review B 104, no. 15 (2021): 155124.
DOI: 10.1103/PhysRevB.104.155124.
Copyright 2022 American Physical Society.
Attribution 4.0 International (CC BY 4.0).
DOE Contract Number(s): AC02-07CH11358; AC02-07CH11358.
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