The Unconventional Upper Critical Field in Noncentrosymmetric Superconductor with Spin-triplet Pairing

Chih-Chieh Chiang^1*, Yen-Chang Tu¹, Hsia-Ling Liang¹, Ssu-Yen Huang¹

¹Department of Physics, National Taiwan University, Taipei, Taiwan

* Presenter:Chih-Chieh Chiang, email:f06222067@ntu.edu.tw

Spin-triplet superconductors with centrosymmetric structure have attracted much attention in exploring Majorana Fermion and quantum information processing. On the other hand, superconductors with noncentrosymmetric crystals have been predicted as the mixture of spin-singlet and spin-triplet states. In this work, we demonstrate the unconventional temperature dependence of upper critical field behavior that occurred in the noncentrosymmetric α-BiPd thin film due to the mixture of singlet and triplet pairing. In addition, we can identify multiple superconducting phase diagrams with temperature and magnetic field transitions between singlet and triplet states. The field-induced transition suggests that α-BiPd will be an important material for studying the key physics of odd-parity (spin-triplet) superconducting states and related quantum properties.

Keywords: Superconductor, Majorana Fermion, Quantum material