Noncentrosymmetric Superconductor BeAu

Published

January 4, 2018

Author(s)

A. Amon, E. Svanidze, R. Cardoso-Gil, M. N. Wilson, H. Rosner, M. Bobnar, W. Schnelle, Jeffrey W. Lynn, R. Gumeniuk, C. Hennig, G. M. Luke, H. Borrmann, A. Leithe-Jasper, Yu Grin

Abstract

In noncentrosymmetric superconductors mixed spin-singlet and spin-triplet pairing can occur. In this work, physical properties of the noncentrosymmetric superconductor, BeAu, were investigated. It was established that BeAu undergoes a structural phase transition from a low-temperature non-centrosymmetric FeSi structure type to a high-temperature structure in the CsCl type at T_s= 860 K. The low-temperature modification exhibits a superconducting transition below T_c = 3.3 K. The values of lower (H_c1 = 32 Oe) and upper (H_c2 = 335 Oe) critical fields are rather small, confirming that this type II (KG0L = 2.3) weakly coupled (λ_e-p = 0.5, δC_e/γnT_c approximately equal}1.26) superconductor can be well understood within the Bardeen-Cooper-Schrieffer theory. The muon spin relaxation analysis indicates that the time-reversal symmetry is preserved when the spin relaxation analysis supporting conventional superconductivity in BeAu. From the density functional band structure calculations, a considerable contribution of the Be electrons to the superconducting state was established. On average, a rather small mass renormalization was found, consistent with the experimental data.

Citation

Physical Review B

Volume

97

Issue

1

Pub Type

Journals

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Keywords

Spin-singlet superconductor, spin triplet pairing, noncentrosymmetric crystal structure, Neutron Diffraction, structural transition, specific heat, Magnetization, BCS theory

Citation

Amon, A. , Svanidze, E. , Cardoso-Gil, R. , Wilson, M. , Rosner, H. , Bobnar, M. , Schnelle, W. , Lynn, J. , Gumeniuk, R. , Hennig, C. , Luke, G. , Borrmann, H. , Leithe-Jasper, A. and Grin, Y. (2018), Noncentrosymmetric Superconductor BeAu, Physical Review B, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=924840 (Accessed October 21, 2025)