Anomalous electronic heat capacity of copper nanowires at sub-Kelvin temperatures

摘要: We have measured the electronic heat capacity of thin film nanowires copper and silver at temperatures 0.1 - 0.3 K; films were deposited by standard electron-beam evaporation. The specific Ag sub-100 nm thickness agrees with bulk value free-electron estimate, whereas that similar Cu exceeds corresponding reference values one order magnitude. origin anomalously high remains unknown for moment. Based on low possibility to devise a tunnel probe thermometer it, form promising absorber material, e.g., micro-wave photon calorimetry.