Bielejec E, Wu W
Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA.
Phys Rev Lett. 2001 Dec 17;87(25):256601. doi: 10.1103/PhysRevLett.87.256601. Epub 2001 Nov 29.
Quench-condensed granular Al films of sheet resistance approximately 10 k Omega/square box display hysteresis and ultraslow, nonexponential relaxation in the resistance when the temperature is varied below 300 mK. The hysteresis is nonlinear and the relaxation time does not obey the Arrhenius form. Furthermore, large resistance fluctuations having a 1/f-type power spectrum are observed at low temperatures, with a low-frequency cutoff which shifts to lower frequencies with decreasing temperature. These observations combine to provide a coherent picture that there exists a new glassy electron state in ultrathin granular Al films, with a growing correlation length at low temperatures.
面电阻约为10kΩ/方盒的骤冷凝聚颗粒铝膜在温度低于300mK变化时显示出磁滞现象以及电阻的超慢、非指数弛豫。磁滞是非线性的，弛豫时间不服从阿仑尼乌斯形式。此外，在低温下观察到具有1/f型功率谱的大电阻波动，其低频截止频率随温度降低向更低频率移动。这些观察结果共同提供了一个连贯的图景：在超薄颗粒铝膜中存在一种新的玻璃态电子态，在低温下其关联长度不断增加。
