Evidence of unconventional superconductivity on the surface of the nodal semimetal CaAg 1-x Pd x P.

Autor: Yano R; Department of Applied Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Aichi, Japan. yano-rikizo@nagoya-u.jp., Nagasaka S; Department of Applied Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Aichi, Japan., Matsubara N; Department of Applied Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Aichi, Japan., Saigusa K; Department of Applied Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Aichi, Japan., Tanda T; Department of Applied Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Aichi, Japan., Ito S; Department of Applied Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Aichi, Japan., Yamakage A; Department of Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Aichi, Japan., Okamoto Y; Department of Applied Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Aichi, Japan. yokamoto@issp.u-tokyo.ac.jp.; Institute for Solid State Physics, the University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, 277-8581, Chiba, Japan. yokamoto@issp.u-tokyo.ac.jp., Takenaka K; Department of Applied Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Aichi, Japan., Kashiwaya S; Department of Applied Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Aichi, Japan. s.kashiwaya@nagoya-u.jp.
Jazyk: angličtina
Zdroj: Nature communications [Nat Commun] 2023 Oct 26; Vol. 14 (1), pp. 6817. Date of Electronic Publication: 2023 Oct 26.
DOI: 10.1038/s41467-023-42535-5
Abstrakt: Surface states of topological materials provide extreme electronic states for unconventional superconducting states. CaAg 1-x Pd x P is an ideal candidate for a nodal-line Dirac semimetal with drumhead surface states and no additional bulk bands. Here, we report that CaAg 1-x Pd x P has surface states that exhibit unconventional superconductivity (SC) around 1.5 K. Extremely sharp magnetoresistance, tuned by surface-sensitive gating, determines the surface origin of the ultrahigh-mobility "electrons." The Pd-doping elevates the Fermi level towards the surface states, and as a result, the critical temperature (T c ) is increased up to 1.7 K from 1.2 K for undoped CaAgP. Furthermore, a soft point-contact study at the surface of Pd-doped CaAgP proved the emergence of unconventional SC on the surface. We observed the bell-shaped conductance spectra, a hallmark of the unconventional SC. Ultrahigh mobility carriers derived from the surface flat bands generate a new class of unconventional SC.
(© 2023. The Author(s).)
Databáze: MEDLINE
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