Energy relaxation in superconducting boron-doped diamond films
We report on our study of the relaxation time of the resistive superconducting state in single-crystalline boron-doped diamond films performed with the technique of amplitude-modulated absorption of (sub-) THz radiation. The films have a carrier density of about 2.5×1021 cm-3, a critical temperature of about 2 K and a high normal-state resistivity ρn~1500 μΩ·cm. Our main result is that the slow electron-phonon relaxation time at low temperatures is governed by a T-2-dependence with a value of 0.7 μs at T = 1.7 K. The high normal-state resistivity and remarkably slow electron-phonon relaxation confirm that superconducting boron-doped diamond films are a prospective material for ultrasensitive superconducting bolometers and resonator detectors.
A. Kardakova, A. Shishkin, A. Semenov, S. Ryabchun, J. Bousquet, D. Eon, B. Sacépé, Th. Klein, E. Bustarret, G. N. Goltsman, and T. M. Klapwijk, Relaxation of the resistive superconducting state in superconducting boron-doped diamond, Phys. Rev. B 93, 064506 (2016)