Designing phase sensitive probes of monopole superconducting order

Journal Article · 22 November 2024 · Physical Review Research

DOI: https://doi.org/10.1103/physrevresearch.6.043189 · OSTI ID:2478587

Frazier, Grayson R.  ^[1]; Zhang, Junjia  ^[2]; Zhang, Junyi  ^[3]; Sun, Xinyu  ^[3]; Li, Yi  ^[3]

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1. Johns Hopkins University, Baltimore, MD (United States); Johns Hopkins University
2. Johns Hopkins University, Baltimore, MD (United States); Princeton University, NJ (United States)
3. Johns Hopkins University, Baltimore, MD (United States)

Distinct from familiar s-, p-, or d-wave pairings, the monopole superconducting order represents a novel class of pairing order arising from nontrivial monopole charge of the Cooper pair. In the weak-coupling regime, this order can emerge when pairing occurs between Fermi surfaces with different Chern numbers in, for example, doped Weyl semimetal systems. However, the phase of monopole pairing order is not well-defined over an entire Fermi surface, making it challenging to design experiments sensitive to both its symmetry and topology. To address this, we propose a scheme based on symmetry and topological principles to identify this elusive pairing order through a set of phase-sensitive Josephson experiments. By examining the discrepancy between global and local angular momentum of the pairing order, we can unveil the monopole charge of the pairing order, including for models with higher pair monopole charge |q_p|=1,2, and 3. We demonstrate the proposed probe of monopole pairing order through analytic and numerical studies of Josephson coupling in models of monopole superconductor junctions. This work opens a promising avenue to uncover the unique topological properties of monopole pairing orders and to distinguish them from known pairing orders based on spherical harmonic symmetry.

• Research Organization: Johns Hopkins University, Baltimore, MD (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); NSF CAREER
• Grant/Contract Number: SC0019331
• OSTI ID: 2478587
• Journal Information: Physical Review Research, Journal Name: Physical Review Research Journal Issue: 4 Vol. 6; ISSN 2643-1564
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English