NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Insensitivity of Sub-Kelvin Electron-Phonon Coupling to Substrate Properties
Published
Author(s)
Jason M. Underwood, Peter J. Lowell, Galen C. O'Neil, Joel N. Ullom
Abstract
We have examined the role of the substrate on electron-phonon coupling in normal metal films of Mn-doped Al at temperatures below 1 K. Normal metal-insulator-superconductor junctions were used to measure the electron temperature in thin metal films as a function of Joule heating power and phonon temperature. Theory suggests that the distribution of phonons available for interaction with electrons in thin metal films may depend on the acoustic properties of the substrate. Namely, that the electron- phonon coupling constant Σ would be larger on the substrate with smaller lattice moduli (smaller sound speed). In contrast, our results indicate that within experimental error, Σ is unchanged among the two acoustically distinct substrates used in our investigation.
Underwood, J.
, Lowell, P.
, O'Neil, G.
and Ullom, J.
(2011),
Insensitivity of Sub-Kelvin Electron-Phonon Coupling to Substrate Properties, Physical Review Letters, [online], https://doi.org/10.1103/PhysRevLett.107.255504
(Accessed October 9, 2025)