Kakeshita T, Uchida S, Kojima K M, Adachi S, Tajima S, Gorshunov B, Dressel M
Department of Superconductivity, University of Tokyo, Yayoi 2-11-16, Bunkyo-ku, Tokyo 113-8656, Japan.
Phys Rev Lett. 2001 Apr 30;86(18):4140-3. doi: 10.1103/PhysRevLett.86.4140.
A transverse optical plasma mode is observed at far-infrared frequencies within the superconducting gap region by measuring the c-axis optical reflectivity for single crystals of T* cuprate superconductors SmLa0.85Sr0.15CuO4-delta and Nd1.4Sr0.4Ce0.2CuO4-delta. These T* cuprates have two different insulating layers sandwiching the superconducting CuO2 planes, leading to two longitudinal plasmons. Also, the transverse mode is directly observed due to the coupling of the infrared radiation with the current perpendicular to the superconducting layers which are regarded as an alternating array of two inequivalent Josephson junctions.
通过测量T铜酸盐超导体SmLa0.85Sr0.15CuO4-δ和Nd1.4Sr0.4Ce0.2CuO4-δ单晶的c轴光反射率，在超导能隙区域内的远红外频率下观察到一种横向光学等离子体模式。这些T铜酸盐有两个不同的绝缘层夹着超导CuO2平面，导致两个纵向等离子体激元。此外，由于红外辐射与垂直于超导层的电流耦合，直接观察到了横向模式，超导层被视为两个不等价约瑟夫森结的交替阵列。
