Campus Units

Physics and Astronomy, Ames Laboratory

Document Type

Article

Publication Version

Published Version

Publication Date

6-1-2015

Journal or Book Title

Physical Review B

Volume

91

Issue

22

First Page

220505(R)

DOI

10.1103/PhysRevB.91.220505

Abstract

We report measurements of the anisotropic upper critical field Hc2(T) for K2Cr3As3 single crystals up to 60 T and T>0.6K. Our results show that the upper critical field parallel to the Cr chains, H∥c2(T), exhibits a paramagnetically limited behavior, whereas the shape of the H⊥c2(T) curve (perpendicular to the Cr chains) has no evidence of paramagnetic effects. As a result, the curves H⊥c2(T) and H∥c2(T) cross at T≈4K, so that the anisotropy parameter γH(T)=H⊥c2/H∥c2(T) increases from γH(Tc)≈0.35 near Tc to γH(0)≈1.7 at 0.6 K. The paramagnetically limited behavior of H∥c2(T) is inconsistent with triplet superconductivity but suggests a form of singlet superconductivity with the electron spins locked onto the direction of Cr chains.

Comments

This article is published as Balakirev, F. F., T. Kong, M. Jaime, R. D. McDonald, C. H. Mielke, A. Gurevich, P. C. Canfield, and S. L. Bud'ko. "Anisotropy reversal of the upper critical field at low temperatures and spin-locked superconductivity in K 2 Cr 3 As 3." Physical Review B 91, no. 22 (2015): 220505. DOI: 10.1103/PhysRevB.91.220505. Posted with permission.

Copyright Owner

American Physical Society

Language

en

File Format

application/pdf

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