Sharp magnetization jump at the first-order superconducting transition in Sr2RuO4
| Autor: | Kittaka, Shunichiro, Kasahara, Akira, Sakakibara, Toshiro, Shibata, Daisuke, Yonezawa, Shingo, Maeno, Yoshiteru, Tenya, Kenichi, Machida, Kazushige |
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| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | Phys. Rev. B 90, 220502(R) (2014) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.90.220502 |
| Popis: | The magnetization and magnetic torque of a high-quality single crystal of Sr$_2$RuO$_4$ have been measured down to 0.1 K under a precise control of the magnetic-field orientation. When the magnetic field is applied exactly parallel to the $ab$ plane, a sharp magnetization jump $4\pi\delta M$ of $(0.74 \pm 0.15)$ G at the upper critical field $H_{{\rm c2},{ab}} \sim 15$ kOe with a field hysteresis of 100 Oe is observed at low temperatures, evidencing a first-order superconducting-normal transition. A strong magnetic torque appearing when $H$ is slightly tilted away from the $ab$ plane confirms an intrinsic anisotropy $\varGamma=\xi_a/\xi_c$ of as large as 60 even at 100 mK, in contrast with the observed $H_{{\rm c2}}$ anisotropy of $\sim 20$. The present results raise fundamental issues in both the existing spin-triplet and spin-singlet scenarios, providing, in turn, crucial hints toward the resolution of the superconducting nature of Sr$_2$RuO$_4$. Comment: 5 pages, 4 figures (main text) + 2 pages, 2 figures (supplemental material), published in Phys. Rev. B |
| Databáze: | arXiv |
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