|
Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Engineering / Faculty of Engineering >
Peer-reviewed Journal Articles, etc >
Odd-frequency Cooper pair around a magnetic impurity
| Title: | Odd-frequency Cooper pair around a magnetic impurity |
| Authors: | Suzuki, Shu-Ichiro Browse this author | | Sato, Takumi Browse this author | | Asano, Yasuhiro Browse this author →KAKEN DB |
| Issue Date: | 29-Sep-2022 |
| Publisher: | American Physical Society (APS) |
| Journal Title: | Physical Review B |
| Volume: | 106 |
| Issue: | 10 |
| Start Page: | 104518 |
| Publisher DOI: | 10.1103/PhysRevB.106.104518 |
| Abstract: | The Yu-Shiba-Rusinov (YSR) state appears as a bound state of a quasiparticle at a magnetic atom embedded in a superconductor. We discuss why the YSR state has energy below the superconducting gap and why the pair potential changes the sign at the magnetic atom. Although a magnetic atom in a superconductor has been considered as a pair breaker since the 1960s, we propose an alternative physical picture to explain these reasons. The analytical expression of the Green's function indicates that a magnetic atom converts a spin-singlet s-wave Cooper pair into odd-frequency Cooper pairs rather than breaking it and that the odd-frequency pairing correlations coexist with the YSR states below the gap. The relationships among the free-energy density, the amplitudes of pairing correlation functions, and the sign change of the pair potential at a magnetic impurity are discussed utilizing the self-consistent solution of the Eilenberger equation. We conclude that the sign change of the pair potential happens only when the amplitudes of odd-frequency pairing correlations are dominant at the magnetic impurity. In the presence of the local pi-phase shift in the pair potential, odd-frequency pairs can decrease the free-energy density there because their response to a magnetic field is paramagnetic. |
| Rights: | ©[2022] American Physical Society |
| Type: | article |
| URI: | http://hdl.handle.net/2115/87281 |
| Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
|
Submitter: 浅野 泰寛
|
