EMP is funded through the Horizon2020 programme of the European Commission.
Selected Publications

Crossover between Electron-Phonon and Boundary-Resistance Limits to Thermal Relaxation in Copper Films

L. B. Wang, O.-P. Saira, D. S. Golubev, J. P. Pekola

We observe a crossover from electron-phonon (e-ph) coupling limited energy relaxation to that governed by thermal boundary resistance (phonon-phonon coupling, ph-ph) in copper films at subkelvin temperatures. Our measurement yields a quantitative picture of heat currents, in terms of temperature dependences and magnitudes, in both e-ph and pp limited regimes, respectively. We show that by adding a third layer in between the copper film and the substrate, the thermal boundary resistance is increased fourfold, consistent with an assumed series connection of thermal resistances.

Phys. Rev. Applied 12, 024051 (2019)

doi: 10.1103/PhysRevApplied.12.024051