Fragility of surface states in topological superfluid ${}^3$He

Abstract

Topological superfluid ${}^3$He, with unconventional spin-triplet p-wave pairing, provides a model system for topological superconductors, which have attracted significant interest through potential applications in topologically protected quantum computing. In topological insulators and quantum Hall systems, the surface/edge states, arising from bulk-surface correspondence and the momentum space topology of the band structure, are robust. Here we demonstrate that in topological superconductors the surface Andreev bound states, which depend on the momentum space topology of the emergent order parameter, are fragile with respect to the details of surface scattering. We confine superfluid ${}^3$He within a cavity of height comparable to the Cooper pair diameter. We precisely determine the superfluid transition temperature $T_{\mathrm{c}}$ and the suppression of the superfluid energy gap, for different scattering conditions tuned in situ, and compare to the predictions of quasi-classical theory. We discover that surface magnetic scattering leads to unexpectedly large suppression of $T_{\mathrm{c}}$, corresponding to an increased density of low energy bound states.

Main text: 10 pages + 4 figures; Supplementary information: 33 pages, 14 figures

References in corpus (16)

• Classification of topological insulators and superconductors in three spatial dimensions
• Majorana bound states in a coupled quantum-dot hybrid-nanowire system
• Spontaneously polarized half-gapped superconductivity
• Evidence of topological superconductivity in planar Josephson junctions
• Topological Superconductivity in a Phase-Controlled Josephson Junction
• Surface States, Edge Currents and the Angular Momentum of Chiral p-wave Superfluids
• Thermodynamic properties of thin films of superfluid 3He-A
• Surface Majorana Cone of the Superfluid ${}^3$He B Phase
• Evidence for a Spatially-Modulated Superfluid Phase of ${}^3$He under Confinement
• Impurity Effects of Aerogel in Superfluid ${}^3$He
• Influence of Magnetic Scattering on Superfluidity of 3He in Nematic Aerogel
• Full proximity treatment of topological superconductors in Josephson-junction architectures
• Fabrication of micro fluidic cavities using Si-to-glass anodic bonding
• A nuclear magnetic resonance spectrometer for operation around 1 MHz with a sub 10 mK noise temperature based on a two stage dc SQUID
• The Effect of Magnetic Impurities on Superfluid ${}^3$He in Aerogel
• Influence of Exchange Scattering on Superfluid He-3 states in Nematic Aerogel

Cited by in corpus (17)

• Direct measurement of the ${}^3$He${}^{+}$ magnetic moments
• Nonlinear two-level dynamics of quantum time crystals
• Quantum bath suppression in a superconducting circuit by immersion cooling
• Supercooling of the A phase of ${}^3$He
• Path-Dependent Supercooling of the ${}^3$He Superfluid A-B transition
• Topological nodal line in superfluid ${}^3$He and the Anderson theorem
• Robust and tunable coreless vortices and fractional vortices in chiral $d$-wave superconductors
• A-B transition in superfluid ${}^3$He and cosmological phase transitions
• Weyl Fermions and Broken Symmetry Phases of Laterally Confined ${}^3$He Films
• Enhanced chiral edge currents and orbital magnetic moment in chiral $d$-wave superconductors from mesoscopic finite-size effects
• Surface State Dissipation in Confined 3He-A
• Transport of bound quasiparticle states in a two-dimensional boundary superfluid
• Magnetic Susceptibility of Andreev Bound States in Superfluid ${}^3$He-B
• Disorder Induced Anomalous Thermal Hall Effect in Chiral Phases of Superfluid ${}^3$He
• Nanofluidic platform for studying the first-order phase transitions in superfluid helium-3
• Chiral superfluid helium-3 in the quasi-two-dimensional limit
• Dimensional crossover of superfluid ${}^3$He in a magnetic field