Transport spectroscopy of induced superconductivity in the three-dimensional topological insulator HgTe

Abstract

The proximity-induced superconducting state in the 3-dimensional topological insulator HgTe has been studied using electronic transport of a normal metal-superconducting point contact as a spectroscopic tool (Andreev point contact spectroscopy). By analyzing the conductance as a function of voltage for various temperatures, magnetic fields and gate-voltages, we find evidence, in equilibrium, for an induced order parameter in HgTe of $70\mu$eV and a niobium order parameter of $1.1$meV. To understand the full conductance curve as a function of applied voltage we suggest a non-equilibrium driven transformation of the quantum transport process where the relevant scattering region and equilibrium reservoirs change with voltage. This implies that the spectroscopy probes the superconducting correlations at different positions in the sample, depending on the bias voltage.

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References in corpus (15)

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Cited by in corpus (22)

• Hierarchy of higher-order topological superconductors in three dimensions
• Creation of spin-triplet Cooper pairs in the absence of magnetic ordering
• Signature of Fermi arc surface states in Andreev reflection at the WTe${}_2$ Weyl semimetal surface
• Creating Majorana modes from segmented Fermi surface
• Subgap states in two dimensional spectroscopy of unconventional superconductors using graphene
• Appearance of the universal value $e^2/h$ of the zero-bias conductance in a Weyl semimetal-superconductor junction
• Proximity-induced superconductivity within the InAs/GaSb edge conducting state
• Topological surface states in thick partially relaxed HgTe film
• Microwave studies of the fractional Josephson effect in HgTe-based Josephson junctions
• Robust and fragile Majorana bound states in proximitized topological insulator nanoribbons
• Conductance oscillations and zero-bias anomaly in a single superconducting junction to a three-dimensional $B{i}_{2}T{e}_3$ topological insulator
• Dirac point formation revealed by Andreev tunneling in superlattice-graphene/superconductor junctions
• Directional electron-filtering at a superconductor-semiconductor interface
• Waiting time distributions in Quantum spin hall based heterostructures
• Magnetically stable zero-bias anomaly in Andreev contact to the magnetic Weyl semimetal Co${}_3$Sn${}_2$S${}_2$
• Cyclotron resonance induced photogalvanic effect in surface states of 200 nm thick strained HgTe films
• Transport in a periodically driven tilted lattice via the extended reservoir approach: Stability criterion for recovering the continuum limit
• Mixed higher-order topology and nodal and nodeless flat band topological phases in a superconducting multiorbital model
• Quasiparticle cooling using a Topological insulator-Superconductor hybrid junction
• Weak antilocalization in partially relaxed 200-nm HgTe films
• Coalescence of Andreev bound states on the surface of a chiral topological semimetal
• Confinement-induced zero-bias peaks in conventional superconductor hybrids