Shot noise of large charge quanta in superconductor/semiconductor/superconductor junctions

Abstract

We have found experimentally that the noise of ballistic electron transport in a superconductor/semiconductor/superconductor junction is enhanced relative to the value given by the general relation, S_V=2eIR^2coth(eV/2kT), for two voltage regions in which this expression reduces to its thermal and shot noise limits. The noise enhancement is explained by the presence of large charge quanta, with effective charge q*=(1+2Delta/eV)e, that generate a noise spectrum S_V=2q*IR^2, as predicted in Phys. Rev. Lett. 76, 3814 (1996). These charge quanta result from multiple Andreev reflections at each junction interface, which are also responsible for the subharmonic gap structure observed in the voltage dependence of the junction's conductance.

arXiv comment5 pages, 5 figures, submitted to Physical Review B as a Rapid Communication. v2 author name in reference corrected. v3 added references. v4 clarifications in the text and reference added thanks to C. Urbina

References in corpus (9)

• Shot Noise in Mesoscopic Conductors
• Hamiltonian approach to the transport properties of superconducting quantum point contacts
• AC JOSEPHSON EFFECT IN A SINGLE QUANTUM CHANNEL
• Observation of Andreev Reflection Enhanced Shot Noise
• Supercurrent noise in quantum point contacts
• Shot noise and coherent multiple charge transfer in superconducting quantum point-contacts
• Multiple Andreev Reflection and Giant Excess Noise in Diffusive Superconductor/Normal-Metal/Superconductor Junctions
• Doubled Full Shot Noise in Quantum Coherent Superconductor - Semiconductor Junctions
• Non-equilibrium current noise in mesoscopic disordered SNS junctions

Cited by in corpus (4)

• Noise and Full Counting Statistics of Incoherent Multiple Andreev Reflection
• Fluctuations of the Josephson current and electron-electron interactions in superconducting weak links
• AC Josephson current and supercurrent noise through one-dimensional correlated electron systems
• Full Counting Statistics of Multiple Andreev Reflections in incoherent diffusive superconducting junctions