Speaker
Description
Muon Knight shift measurements are a well-established method for determining pairing symmetries in superconductors, particularly effective for $f$-electron-based heavy fermion superconductors. However, precise measurements remain challenging in $d$-electron-based superconductors such as Sr$_2$RuO$_4$, where the Knight shift is intrinsically an order of magnitude smaller.
In this talk, we present high-precision muon Knight shift measurements of superconducting Sr$_2$RuO$_4$. We found that using multiple crystal pieces, commonly employed in $\mu$SR experiments, causes a serious problem in an applied magnetic field, due to stray fields from neighboring diamagnetic crystals. Thus, one crystal piece was used in this study. We achieve enhanced sensitivity to subtle frequency shifts across the superconducting transition temperature, $T_c$, by carefully separating the various contributions to the shift. This separation was made possible by measuring the SQUID bulk magnetization of the identical Sr$_2$RuO$_4$ crystal used in the muon Knight shift experiments, under very similar conditions. We determine the muon Knight shift of Sr$_2$RuO$_4$ in the normal state and confirm a significant reduction below $T_c$, consistent with spin-singlet-like pairing. This result highlights the potential of $\mu$SR as a powerful complementary technique to the established method of nuclear magnetic resonance (NMR) for probing spin susceptibility in superconductors.
| matsuki.hisakazu.2i@kyoto-u.ac.jp | |
| Funding Agency | Toyota Riken |
| Supervisors Name | Yoshiteru Maeno |
| Supervisors Email | maeno.yoshiteru.b04@kyoto-u.jp |
| Did you request an Invitation Letter for a Visitors Visa Application | No |
