Josephson plasma resonance in a single-layered cuprateBi2(Sr,La)2CuOy

S. Sakamoto, A. Maeda, T. Hanaguri, Y. Kotaka, J. Shimoyama, K. Kishio, Y. Matsushita, M. Hasegawa, H. Takei, H. Ikeda, R. Yoshizaki
1996 Physical Review B (Condensed Matter)  
Microwave absorption was measured in the mixed state of ͑Bi or Tl͒ 2 ͑Sr or Ba͒ 2 Ca nϪ1 Cu n O y . In a La-substituted Bi 2 Sr 2 CuO y ͑Bi-2201͒, a sharp resonant structure was found in the absorption as a function of magnetic field only when the microwave current flowed across the CuO 2 planes, as well as in Bi 2 Sr 2 CaCu 2 O y ͑Bi-2212͒. Together with the frequency-dependence data, the resonant structure in the absorption in Bi-2201 is considered to be the Josephson plasma resonance. The
more » ... a resonance. The anisotropy ratio ␥ϵ(m c /m ab ) 1/2 was tentatively estimated to be ϳ750. A striking difference was found in the temperature dependence of the resonance field between Bi-2201 and Bi-2212. We argue that this comes from the difference in the dimensionality of the vortex systems. In Tl 2 Ba 2 CaCu 2 O y , no such resonance was found in the microwave region, which is probably due to a smaller anisotropy in this material.
doi:10.1103/physrevb.53.r14749 pmid:9983346 fatcat:72gbp44nafhzrnqr6ayoboiqne