Search for spontaneous magnetization in noncentrosymmetric superconductors

TMU International Symposium on "New Quantum Phases Emerging from Novel Crystal Structure"

Sumiyama, A.^1 ; Kawakatsu, D.^1 ; Gouchi, J.^1 ; Kawasaki, I.^1 ; Yamaguchi, A.^1 ; Motoyama, G.^2 ; Hirose, Y.^3 ; Settai, R.^3 ; Onuki, Y.^4

Graduate School of Material Science, University of Hyogo, Kamigori, Hyogo

678-1297, Japan^1

Department of Material Science, Shimane University, Shimane, Matsue

690-8504, Japan^2

Department of Physics, Niigata University, Nishi-ku, Niigata

950-2181, Japan^3

Department of Physics and Earth Sciences, University of the Ryukyus, Nishihara, Okinawa

903-0213, Japan^4

关键词: Meissner effect;    Noncentrosymmetric superconductors;    Spontaneous magnetization;    SQUID magnetometers;    Superconducting phase;    Superconducting state;    Time reversal symmetries;    Zero magnetic fields;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/683/1/012029/pdf
DOI  :  10.1088/1742-6596/683/1/012029

来源: IOP

【 摘 要 】

We have measured the magnetization of two noncentrosymmetric superconductors: Ir2Ga9and CePt3Si using a SQUID magnetometer, neither of which has been tested for the time-reversal symmetry in the superconducting state. For Ir2Ga9, the magnetization change ΔM below the superconducting transition temperature Tc∼ 2.2 K was smaller than 10-5G in zero magnetic field, suggesting that ΔM originates in the Meissner effect induced by the possible residual field. When CePt3Si was cooled in zero magnetic field, ΔM along the c axis first decreased below Tc+∼ 0.75 K (high-Tcphase) and then increased below Tc-∼ 0.45 K (bulk superconducting phase). Since this behavior cannot be explained by the Meissner effect, it may be a sign of a spontaneous magnetization.