title: Observation of the transverse optical plasmon in SmLa0.8Sr0.2CuO4-delta.
abstract: We present microwave and infrared measurements on SmLa0.8Sr0.2CuO4-delta, which are direct evidence for the existence of a transverse optical plasma mode, observed as a peak in the c-axis optical conductivity. This mode appears as a consequence of the existence of two different intrinsic Josephson couplings between the CuO2 layers, one with a Sm2O2 block layer, and the other one with a (La,Sr)2O2-delta block layer. From the frequencies and the intensities of the collective modes we determine the value of the compressibility of the two dimensional electron fluid in the copper oxygen planes.
authors.affiliation: Laboratory of Solid State Physics, Materials Science Centre, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
authors.forename: D
authors.initials: D
authors.lastname: Dulić
authors.forename: A
authors.initials: A
authors.lastname: Pimenov
authors.forename: D
authors.initials: D
authors.lastname: van der Marel
authors.forename: D M
authors.initials: DM
authors.lastname: Broun
authors.forename: S
authors.initials: S
authors.lastname: Kamal
authors.forename: W N
authors.initials: WN
authors.lastname: Hardy
authors.forename: A A
authors.initials: AA
authors.lastname: Tsvetkov
authors.forename: I M
authors.initials: IM
authors.lastname: Sutjaha
authors.forename: R
authors.initials: R
authors.lastname: Liang
authors.forename: A A
authors.initials: AA
authors.lastname: Menovsky
authors.forename: A
authors.initials: A
authors.lastname: Loidl
authors.forename: S S
authors.initials: SS
authors.lastname: Saxena