arXiv subjects

Yu. I. Latyshev

Publications and source records attributed to Yu. I. Latyshev.

21 records · Page 2Linked to original sources

arXiv1999

High-Field Quasiparticle Tunneling in Bi_2Sr_2CaCu_2O_8+delta: Negative Magnetoresistance in the Superconducting State

We report on the c-axis resistivity rho_c(H) in Bi_2Sr_2CaCu_2O_{8+δ} that peaks in quasi-static magnetic fields up to 60 T. By suppressing the Josephson part of the two-channel (Cooper pair/quasiparticle) conductivity σ_c (H), we find that the negative slope of ρ_c(H) above the peak is due to quasiparticle tunneling conductivity σ_q(H) across the CuO_2 layers below H_{c2}. At high fields (a) σ_q(H) grows linearly with H, and (b) ρ_c(T) tends to saturate (sigma_c \neq 0) as T->0, consistent with the scattering at the nodes of the d-gap. A superlinear sigma_q(H) marks the normal state above T_c.

cond-mat.supr-con↗

arXiv1999

Interlayer Transport of Quasiparticles and Cooper pairs in Bi2Sr2CaCu2O8+y Superconductors

We study the c-axis transport of stacked, intrinsic junctions in Bi2Sr2CaCu2O8+y single crystals, fabricated by the double-sided ion beam processing technique from single crystal whiskers. Measurements of the I-V characteristics of these samples allow us to obtain the temperature and voltage dependence of the quasiparticle c-axis conductivity in the superconducting state, the Josephson critical current, and the superconducting gap. We show that the BCS d-wave model in the clean limit for resonant impurity scattering with a significant contribution from coherent interlayer tunneling, describes satisfactorily the low temperature and low energy c-axis transport of both quasiparticles and Cooper pairs.

cond-mat.supr-con↗

arXiv1999

Experimental Evidence for Coulomb Charging Effects in the Submicron Bi-2212 Stacks

We developed the focused ion beam (FIB) and ion milling techniques for a fabrication of the Bi_2Sr_2CaCu_2O_{8+δ} (Bi-2212) stacked junctions with in-plane size L_{ab} from several microns down to the submicron scale without degradation of T_c. We found that behaviour of submicron junctions (L_{ab} < 1 μm) is quite different from the bigger ones. The critical current density is considerably suppressed, the hysteresis and multibranched structure of the IV characteristics are eliminated, the periodic structure of current peaks reproducibly appears on the IV curves at low temperatures. A period of the structure, ΔV, is consistent with the Coulomb charging energy of a single pair, ΔV = e/C with C the effective capacitance of the stack. We consider this behaviour to originate from the Coulomb blockade of the intrinsic Josephson tunneling in submicron Bi-2212 stacks.

cond-mat.supr-con↗