Modification of electron-phonon coupling by micromachining and suspension
Abstract
Weak electron-phonon interaction in metals at low temperatures forms the basis of operation for cryogenic hot-electron bolometers and calorimeters. Here, we develop a thermometry scheme based on proximity supercurrent to study the thermal response of a thin gold film on a SiO₂ platform at temperatures below 100 mK. We find that the exponent of the power law describing electron-phonon coupling in the film drops by approximately 1/2 as the platform is micromachined and released from its substrate. This contrasts the conventional theory for bulklike geometries that predicts integer-valued exponents. We attribute the fractional change to a modified phonon spectrum described by recent theoretical developments.
Additional Information
© 2020 Published under license by AIP Publishing. Submitted: 21 October 2019; Accepted: 18 December 2019; Published Online: 14 January 2020. We thank D.-V. Anghel for important discussions during the preparation of the manuscript. This material is based upon work supported by, or in part by, the U.S. Army Research Laboratory and the U.S. Army Research Office under Contract Nos. W911NF-13-1-0390 and W911NF-18-1-0028, and the Academy of Finland under Contract No. 312057.Attached Files
Published - 1.5132948.pdf
Submitted - 1910.10126.pdf
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Additional details
- Eprint ID
- 100321
- Resolver ID
- CaltechAUTHORS:20191216-162059894
- W911NF-13-1-0390
- Army Research Laboratory
- W911NF-18-1-0028
- Army Research Office (ARO)
- 312057
- Academy of Finland
- Created
-
2019-12-17Created from EPrint's datestamp field
- Updated
-
2021-11-16Created from EPrint's last_modified field
- Caltech groups
- Kavli Nanoscience Institute, Division of Biology and Biological Engineering