Tunneling spectroscopy of topological superconductors

Abstract

Tunneling conductance spectra of normal metal/insulator/superconductor (N/I/S) junctions are calculated to determine the potential of tunneling spectroscopy in investigations of topological superconductivity. Peculiar feature of topological superconductors is the formation of gapless edge states in them. Since the conductance of N/I/S junctions is sensitive to the formation of these edge states, topological superconductivity can be identified through edge-state detection. Herein, the effects of Fermi surface anisotropy and an applied magnetic field on the conductance spectra are analyzed to gather indications that can help to identify the topological nature of actual materials.Comment: 17pages, 1 table, 6 figures, submitted to Physica

Enhanced superconductivity at the interface ofW/Sr2RuO4point contacts

“…Such chiral order is expected to generate edge currents, but the expected magnetic field due to edge currents has not been directly observed with local field imaging, [6][7][8] though there is indirect evidence of edge currents revealed by in-plane tunneling spectroscopy 9,10 and point contact spectroscopy (PCS), 11 both with assumptions to fit the conductance spectra.…”

Probing chiral superconductivity in Sr2RuO4underneaththe surface by point contact measurements

“…Nevertheless, indirect evidence of p-wave superconductivity was reported in local transport measurements, including (scanning) tunnel junction spectroscopy [17][18][19][20] and point contact spectroscopy (PCS) [21,22],…”

“…With alternating fields, the observed hysteresis in magnetoresistance can be explained by domain dynamics, providing support for the existence of chiral domains. The origin of the strong pinning could be the chiral domains themselves.where the symmetry of the order parameter may be inferred by fitting the conductance spectra [19,20], but this method may not distinguish the chiral edge states from helical states [23].Unlike the above-mentioned local transport measurements, here we conduct PC measurements on the SRO-Ru eutectic system [24]. In the eutectic system, micrometer-sized Ru inclusions are embedded in SRO with an atomically sharp interface.…”

“…where the symmetry of the order parameter may be inferred by fitting the conductance spectra [19,20], but this method may not distinguish the chiral edge states from helical states [23].…”

Influence of the impurity scattering on charge transport in unconventional superconductor junctions

“…The angle-resolved conductance spectra in Figs. 9(c)-9(e) display double-chiral states owing to a Chern number ch = 2 [81,82].…”