Millisecond electron–phonon relaxation in ultrathin disordered metal films at millikelvin temperatures

作者：M. E. Gershenson, Donglai Gong, Toshiyuki Sato, Boris S. Karasik, Andrei V. Sergeev · 发表于：Applied Physics Letters · 年份：2001 · DOI：10.1063/1.1407302 · 被引用次数：74 · 研究领域：Superconducting and THz Device Technology、Thermal Radiation and Cooling Technologies、Physics of Superconductivity and Magnetism

We have measured directly the thermal conductance between electrons and phonons in ultrathin Hf and Ti films at millikelvin temperatures. The experimental data indicate that electron–phonon coupling in these films is significantly suppressed by disorder. The electron cooling time τε follows the T−4 dependence with a record-long value τε=25 ms at T=0.04 K. The hot-electron detectors of far-infrared radiation, fabricated from such films, are expected to have a very high sensitivity. The noise-equivalent power of a detector with the area 1 μm2 and the noise limited by fluctuations of the temperature are expected to be (2–3)×10−20 W/Hz, which is two orders of magnitude smaller than that of the state-of-the-art bolometers.