Unconventional quantum oscillations in mesoscopic rings of spin-triplet superconductor Sr2RuO4

作者：Cai X^*; Ying Y A; Staley N E; Xin Y; Fobes D; Liu T J; Mao Z Q; Liu Y

来源：Physical Review B, 2013, 87(8): 081104.

DOI：10.1103/PhysRevB.87.081104

The odd-parity, spin-triplet superconductor Sr2RuO4 has been found to feature exotic vortex physics including half-flux quanta trapped in a doubly connected sample and the formation of vortex lattices at low fields. The consequences of these vortex states on the low-temperature magnetoresistive behavior of mesoscopic samples of Sr2RuO4 were investigated by using a ring device fabricated on mechanically exfoliated single crystals of Sr2RuO4 by photolithography and a focused ion beam. With the magnetic field applied perpendicular to the in-plane direction, thin-wall rings of Sr2RuO4 were found to exhibit pronounced quantum oscillations with a conventional period of the full-flux quantum even though the unexpectedly large amplitude and the number of oscillations suggest the observation of vortex-flow-dominated magnetoresistance oscillations rather than a conventional Little-Parks effect. For rings with a thick wall, two distinct periods of quantum oscillations were found in high-and low-field regimes, respectively, which we argue to be associated with the %26quot;lock-in%26quot; of a vortex lattice in these thick-wall rings. No evidence for half-flux-quantum resistance oscillations were identified in any sample measured so far without the presence of an in-plane field. DOI: 10.1103/PhysRevB.87.081104

• 出版日期2013-2-14