Existence of an Independent Phonon Bath in a Quantum Device

Abstract

At low temperatures, the thermal wavelength of acoustic phonons in a metallic thin film on a substrate can widely exceed the film thickness. It is thus generally believed that a mesoscopic device operating at low temperature does not carry an individual phonon population. In this work, we provide direct experimental evidence for the thermal decoupling of phonons in a mesoscopic quantum device from its substrate phonon heat bath at a sub-Kelvin temperature. A simple heat balance model assuming an independent phonon bath following the usual electron-phonon and Kapitza coupling laws can account for all experimental observations.

References in corpus (8)

• The Josephson heat interferometer
• Micrometre-scale refrigerators
• Andreev Current-Induced Dissipation in a Hybrid Superconducting Tunnel Junction
• Phonon cooling of nanomechanical beams with tunnel junctions
• Electron and phonon Cooling in a Superconductor - Normal Metal - Superconductor Tunnel Junction
• Influence of Phonon dimensionality on Electron Energy Relaxation
• Electron-phonon coupling and longitudinal mechanical-mode cooling in a metallic nanowire
• Electronic cooling of a submicron-sized metallic beam

Cited by in corpus (10)

• Fast electron thermometry towards ultra-sensitive calorimetric detection
• Microwave nanobolometer based on proximity Josephson junctions
• Electronic coolers based on superconducting tunnel junctions: fundamentals and applications
• Superconducting cascade electron refrigerator
• Low-temperature electron-phonon heat transfer in metal films
• Crossover between electron-phonon and boundary resistance limited thermal relaxation in copper films
• High-performance electronic cooling with superconducting tunnel junctions
• Thermal resistance in superconducting flip-chip assemblies
• Sub-50 mK electronic cooling with large-area superconducting tunnel junctions
• Mesoscopic electron transport and atomic gases, a review of Frank W. J. Hekking's scientific work