Observation of Odd-Parity Superconductivity with the Geshkenbein-Larkin-Barone Composite Rings

Xiaoying Xu, Yufan Li, and C. L. Chien

Phys. Rev. Lett. 132, 056001 – Published 29 January 2024

Abstract

Phase-sensitive measurements on a composite ring made of a superconductor of interest connected by a known singlet $s$ -wave superconductor can unambiguously determine its pairing symmetry. In composite rings with epitaxial $β − {Bi}_{2} Pd$ and $s$ -wave Nb, we have observed half-integer-quantum flux when Nb is connected to the opposite crystalline ends of $β − {Bi}_{2} Pd$ and integer-quantum flux when Nb is connected to the same crystalline ends of $β − {Bi}_{2} Pd$ . With ascending temperature, the half-integer-flux quantization transits to integer-flux quantization, before the eventual loss of phase coherence. These findings point to odd-parity pairing symmetry in superconducting $β − {Bi}_{2} Pd$ .

Received 25 January 2023
Revised 25 November 2023
Accepted 19 December 2023

DOI:https://doi.org/10.1103/PhysRevLett.132.056001

Physics Subject Headings (PhySH)

Pairing mechanisms Spin-triplet pairing Superconducting gap Superconducting order parameter p-wave s-wave

Low-temperature superconductors SQUID Superconducting devices

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Xiaoying Xu ^1,*, Yufan Li ^1,2,†, and C. L. Chien ^1,3,‡

¹William H. Miller III Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
²Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
³Department of Physics, National Taiwan University, Taipei 10617, Taiwan

^*Corresponding author: ustbxuxiaoying@gmail.com Present address: Quantum Science Center of Guangdong-HongKong-Macao Greater Bay Area, Shenzhen, Guangdong, China.
^†Corresponding author: yufanli@cuhk.edu.hk
^‡Corresponding author: clchien@jhu.edu