Little-Parks oscillations with half-quantum fluxoid features in Sr2RuO4 micro rings

Abstract

In a micro ring of a superconductor with a spin-triplet equal-spin pairing state, a fluxoid, a combined object of magnetic flux and circulating supercurrent, can penetrate as half-integer multiples of the flux quantum. A candidate material to investigate such half-quantum fluxoids is Sr${}_2$RuO${}_4$. We fabricated Sr${}_2$RuO${}_4$ micro rings using single crystals and measured their resistance behavior under magnetic fields controlled with a three-axes vector magnet. Proper Little-Parks oscillations in the magnetovoltage as a function of an axially applied field, associated with fluxoid quantization are clearly observed, for the first time using bulk single crystalline superconductors. We then performed magnetovoltage measurements with additional in-plane magnetic fields. By carefully analyzing both the voltages $V_{+}$ ($V_{-}$) measured at positive (negative) current, we find that, above an in-plane threshold field of about 10 mT, the magnetovoltage maxima convert to minima. We interpret this behavior as the peak splitting expected for the half-quantum fluxoid states.

arXiv comment16 pages, 15 figures

References in corpus (32)

• Topological insulators and superconductors
• Signatures of Majorana fermions in hybrid superconductor-semiconductor nanowire devices
• Paired states of fermions in two dimensions with breaking of parity and time-reversal symmetries, and the fractional quantum Hall effect
• Observation of Majorana Fermions in Ferromagnetic Atomic Chains on a Superconductor
• Non-abelian statistics of half-quantum vortices in p-wave superconductors
• Time-Reversal Symmetry Breaking Superconductivity in Sr2RuO4
• High Resolution Polar Kerr Effect Measurements of Sr2RuO4: Evidence for Broken Time Reversal Symmetry in the Superconducting State
• Evaluation of Spin-Triplet Superconductivity in Sr2RuO4
• Chiral Superconductors
• Strong Peak in $T_c$ of Sr${}_2$RuO${}_4$ Under Uniaxial Pressure
• Observation of half-height magnetization steps in Sr2RuO4
• A polarized neutron-scattering study of the Cooper-pair moment in Sr2RuO4
• Limits on Superconductivity-Related Magnetization in Sr${}_2$RuO${}_4$ and PrOs${}_4$Sb${}_{12}$ from Scanning SQUID Microscopy
• Edge states of Sr${}_2$RuO${}_4$ detected by in-plane tunneling spectroscopy
• Fusion rules and vortices in $p_x+i{p}_y$ superconductors
• First-Order Superconducting Transition of Sr2RuO4
• Stability of half-quantum vorticies in p_x+ip_y superconductors
• Vertical line nodes in the superconducting gap structure of Sr2RuO4
• Direct penetration of spin-triplet superconductivity into a ferromagnet in Au/SrRuO3/Sr2RuO4 junctions
• Spin polarization of half-quantum vortex in systems with equal spin pairing
• Higher-Tc superconducting phase in Sr2RuO4 induced by uniaxial pressure
• Sharp magnetization jump at the first-order superconducting transition in Sr2RuO4
• Anomalous switching in Nb/Ru/Sr2RuO4 topological junctions by chiral domain wall motion
• Specific-heat evidence of the first-order superconducting transition in Sr2RuO4
• Dislocations and the enhancement of superconductivity in odd-parity superconductor Sr${}_2$RuO${}_4$
• Unconventional quantum oscillations in mesoscopic rings of spin-triplet superconductor Sr2RuO4
• Nucleation of superconductivity in a mesoscopic loop of varying width
• Multi-component order parameter superconductivity of Sr${}_2$RuO${}_4$ revealed by topological junctions
• Compact AC Susceptometer for Fast Sample Characterization down to 0.1 K
• Effect of half-quantum vortices on magnetoresistance of perforated superconducting films
• Absence of ${}^{17}$O Knight-Shift Changes across the First-Order Phase Transition Line in Sr${}_2$RuO${}_4$
• Magnetoresistance oscillations and the half-flux-quantum state in spin-triplet superconductor Sr2RuO4

Cited by in corpus (22)

• Observation of Half-Quantum Flux in Unconventional Superconductor $\beta$-Bi${}_2$Pd
• Time-Reversal Invariant Superconductivity of Sr${}_2$RuO${}_4$ Revealed by Josephson Effects
• Symmetry-based approach to nodal structures: Unification of compatibility relations and gapless point classifications
• Evidence of a two-component order parameter in 4Hb-TaS2 in the Little-Parks effect
• Spontaneous emergence of Josephson junctions in homogeneous rings of single-crystal Sr2RuO4
• Chirality-controlled spontaneous currents in spin-orbit coupled superconducting rings
• Superconductivity in Sr${}_2$RuO${}_4$ thin film under biaxial strain
• Constraints on the superconducting state of Sr${}_2$RuO${}_4$ from elastocaloric measurements
• Identifying possible pairing states in Sr${}_2$RuO${}_4$ by tunneling spectroscopy
• Spin susceptibility for orbital-singlet Cooper pair in the three-dimensional Sr${}_2$RuO${}_4$ superconductor
• Magnetoresistance oscillation study of the half-quantum vortex in doubly connected mesoscopic superconducting cylinders of Sr2RuO4
• Possible two-component spin-singlet pairings in Sr2RuO4
• Theoretical studies for identifying horizontal line nodes via angle-resolved density of states measurements ---Application to Sr${}_2$RuO${}_4$---
• A Review of Electronic Transport in Superconducting Sr${}_2$RuO${}_4$ Junctions
• Half-quantum vortices on c-axis domain walls in chiral p-wave superconductors
• Little-Parks oscillation and $\mathbf{d}$-vector texture in spin-triplet superconducting rings with bias current
• Symmetry properties of superconducting order parameter in Sr${}_2$RuO${}_4$
• Flux-periodic oscillations in proximitized core-shell nanowires
• Theory of the Little-Parks effect in spin-triplet superconductors
• Half-quantum flux in spin-triplet superconducting rings with bias current
• Observation of the crossover from quantum fluxoid to half-quantum fluxoid in a chiral superconducting device
• Current-induced superconducting anisotropy of Sr${}_2$RuO${}_4$