Photon assisted tunneling of high order multiple Andreev reflections in epitaxial nanowire Josephson junctions

Abstract

Semiconductor/superconductor hybrids exhibit a range of phenomena that can be exploited for the study of novel physics and the development of new technologies. Understanding the origin the energy spectrum of such hybrids is therefore a crucial goal. Here, we study Josephson junctions defined by shadow epitaxy on InAsSb/Al nanowires. The devices exhibit gate-tunable supercurrents at low temperatures and multiple Andreev reflections (MARs) at finite voltage bias. Under microwave irradiation, photon assisted tunneling (PAT) of MARs produces characteristic oscillating sidebands at quantized energies, which depend on MAR order, $n$, in agreement with a recently suggested modification of the classical Tien-Gordon equation. The scaling of the quantized energy spacings with microwave frequency provides independent confirmation of the effective charge $ne$ transferred by the $n^{\mathrm{th}}$ order tunnel process. The measurements suggest PAT as a powerful method for assigning the origin of low energy spectral features in hybrid Josephson devices.

References in corpus (12)

• Majorana Fermions and a Topological Phase Transition in Semiconductor-Superconductor Heterostructures
• Majorana bound states in a coupled quantum-dot hybrid-nanowire system
• Epitaxy of Semiconductor-Superconductor nanowires
• Tunable Supercurrent Through Semiconductor Nanowires
• Hard gap in epitaxial semiconductor-superconductor nanowires
• Even-odd effect in Andreev Transport through a Carbon Nanotube Quantum Dot
• Transparent Semiconductor-Superconductor Interface and Induced Gap in an Epitaxial Heterostructure Josephson Junction
• Kondo-Enhanced Andreev Tunneling in InAs Nanowire Quantum Dots
• Conduction Channels of an InAs-Al nanowire Josephson weak link
• Superconducting atomic contacts under microwave irradiation
• Multiple Andreev reflections in a quantum dot coupled to superconductors: Effects of spin-orbit coupling
• Proximity Induced Superconductivity in CdTe-HgTe Core-Shell Nanowires

Cited by in corpus (3)

• Quantifying quantum coherence of multiple-charge states in tunable Josephson junctions
• Microwave-induced conductance replicas in hybrid Josephson junctions without Floquet-Andreev states
• Nonequilibrium Andreev resonances in ballistic graphene Andreev interferometers