Abnormal transport properties of Bi-III superconducting phase in pressurized bismuth single crystal

• Published in: Superconductor science & technology Vol. 34; no. 7; pp. 75009 - 75015
• Main Authors: Zhang, Yufeng, Gouchi, Jun, Ishigaki, Kento, Nagasaki, Shoko, Shi, Zhixiang, Uwatoko, Yoshiya
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.07.2021
• Subjects: Bi-III superconducting phase; magneto-resistance; non-Fermi liquid; pressure effect
• ISSN: 0953-2048; 1361-6668
• DOI: 10.1088/1361-6668/abff13

Abstract Resistivity, magnetoresistance, and upper critical field, have been comprehensively studied for the bismuth (Bi)-III superconducting phase in the pressure range of 2.9 GPa ⩽ P ⩽ 6.2 GPa. It is discovered that the transition temperature T c of the Bi-III phase is gradually suppressed with increasing pressure. Strikingly, the temperature-dependent resistivity above T c in the Bi-III region reveals notable non-Fermi-liquid behaviors, resembling many unconventional superconducting systems. As the pressure increases, the magnetoresistance effect progressively grows and reaches a maximum value of 212% at pressure ∼6.2 GPa and field of 5 T, indicating a possible contribution to the charge conduction by Dirac electrons. Moreover, the zero-temperature upper critical field for the Bi-III phase displays relatively low values concerning the moderate T c values, and the reduced upper critical field for different pressures deviates from the single-band Werthamer–Helfand–Hohenberg model. These unusual normal state transport properties and unique behavior of the upper critical field point to possible unconventional superconductivity for the Bi-III superconducting phase.