Search for the superconducting multiphases in Sr2RuO4
Abstract
Successive experiments have revealed that Sr2RuO4 (Tc0=1.5 K) is a spin-triplet superconductor with nodeless gap in low fields. Because of allowed degree of freedom of Cooper-pair-symmetry, multiple phases in Sr2RuO4 can be expected like in UPt3. One of the most promising candidates is a line-node state at higher fields parallel to the ab-plane. To search for this state, we investigated its superconducting behaviour under the fields parallel to the ab-plane by ac susceptibility and specific heat. We detected a clear additional transition feature below Hc2 in both measurements. In addition, we observed that the in-plane upper critical field Hc2 exhibits a four-fold anisotropy of about 3% at 0.35 K. Furthermore, this Hc2 anisotropy has intimate relation with the additional transition feature: Both disappear simultaneously above 0.8 K or under intentional misalignments of less than 1 deg. Most of these characteristics are consistent with the expected line-node gap state.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2000
- Bibcode:
- 2000APS..MARR12002M