Pressure-induced ideal Weyl semimetal state in the layered antiferromagnet EuCd2As2

Abstract

The rich nontrivial topological phases rooted in the interplay between magnetism and topology in the layered antiferromagnet EuCd2As2 have captured vast attention, especially the ideal Weyl semimetal state realized in the spin-polarized ferromagnetic (FM) structure driven by a moderate external magnetic field. In this work, combining high-pressure magnetotransport measurements, structure chracterizations and first principles calculations, we find that application of pressure can also realize the ideal Weyl state in EuCd2As2 through driving the in-plane antiferromagnetic state across an intermediate in-plane FM state then into the out-of-plane FM state. Our high-pressure angle dispersive X-ray diffraction and X-ray absorption near-edge spectroscopy measurements excluded structure transition and/or change of Eu2+ valence state as the sources for the magnetic phase transitions. Alternatively, the apparently reduced axial ratio (c/a) and compressed Eu-layer space distance should play important roles. Our result provides an alternative way to realize the ideal Weyl semimetal state in EuCd2As2 and would be instructive for the exploration of exotic topological properties in such layered magnetic topological phase with strongly competing magnetic exchanges by using high pressure.

main text 16 pages,4 figures and SI 8 pages, 4 figures

References in corpus (8)

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• Generalized gradient approximation for solids and their surfaces
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Cited by in corpus (5)

• The discovery of three-dimensional Van Hove singularity
• Absence of Weyl nodes in EuCd${}_2$As${}_2$ revealed by the carrier density dependence of the anomalous Hall effect
• Intrinsic insulating transport characteristics in low-carrier density EuCd2As2 films
• Revealing the EuCd_{2}As_{2} Semiconducting Band Gap via n-type La-Doping
• Recent advances in understanding and manipulating magnetic and electronic properties of Eu$M_2{X}_2$ ($M$ = Zn, Cd; $X$ = P, As)