533 citations · 3.2k across the 59 of their papers we have counts for
17 papers · 1 filter
Global room-temperature superconductivity in graphite
Y. V. Kopelevich, J. H. S. Torres, R. Ricardo da Silva +3
Room temperature superconductivity under normal conditions has been a major challenge of physics and material science since its very discovery. Here we report the global room-tempe…
Magnetization of BiSrCaCuO micrometer thin ring and its depinning line
B. Semenenko, B. C. Camargo, A. Setzer +3
We demonstrate a geometrical effect on the depinning line (DL) of the flux line lattice of the BiSrCaCuO high-T superconductor (HTSC) micrometer ring.…
Macroscopic-ranged proximity effect in graphite
Bruno Cury Camargo, Piotr Gierlowski, Marek Kuzmiak +4
We report the observation of proximity effect in measurements performed on highly oriented pyrolitic graphite (HOPG) samples when electrical current is injected through the superco…
Unstable and elusive superconductors
Yakov Kopelevich, Robson R. da Silva, Bruno C. Camargo
We briefly review earlier and report original experimental results in the context of metastable or possible superconducting materials. We show that applied electric field induces c…
Extraordinary magnetoresistance in graphite: experimental evidence for the time-reversal symmetry breaking
Y. Kopelevich, R. R. da Silva, A. S. Alexandrov
The ordinary magnetoresistance (MR) of doped semiconductors is positive and quadratic in a low magnetic field, B, as it should be in the framework of the Boltzmann kinetic theory o…
Possible superconductivity in multi-layer-graphene by application of a gate voltage
A. Ballestar, P. Esquinazi, J. Barzola-Quiquia +4
The carrier density in tens of nanometers thick graphite samples (multi-layer-graphene, MLG) has been modified by applying a gate voltage () perpendicular to the graphene plan…
Local and Global Superconductivity in Bismuth
Luis A. Baring, Robson R. da Silva, Yakov Kopelevich
We performed magnetization M(H,T) and magnetoresistance R(T,H) measurements on powdered (grain size ~ 149 micrometers) as well as highly oriented rhombohedral (A7) bismuth (Bi) sam…
Magnetization Measurement of a Possible High-Temperature Superconducting State in Amorphous Carbon Doped with Sulfur
Israel Felner, Yakov Kopelevich
Magnetization M(T,H) measurements performed on thoroughly characterized commercial amorphous carbon powder doped with sulfur (AC-S), revealed the occurrence of an inhomogeneous sup…
FFLO State and Peak Effect Dynamics in CeCoIn_5: Magnetization Studies
X. Gratens, L. Mendonca Ferreira, Y. Kopelevich +6
Magnetization measurements were performed on CeCoIn_5 at temperature down to 30 mK with the magnetic field applied in three different orientations: parallel, near parallel (…
Interaction Between Superconducting and Ferromagnetic Order Parameters in Graphite-Sulfur Composites
S. Moehlecke, Y. Kopelevich, M. B. Maple
The superconductivity of graphite-sulfur composites is highly anisotropic and associated with the graphite planes. The superconducting state coexists with the ferromagnetism of pur…
Vortex Lattice in Bi_{2}Sr_{2}CaCu_{2}O_{8+δ} Well Above the First-Order Phase-Transition Boundary
J. H. S. Torres, R. Ricardo da Silva, S. Moehlecke +1
Measurements of non-local in-plane resistance originating from transverse vortex-vortex correlations have been performed on a Bi_{2}Sr_{2}CaCu_{2}O_{8+δ} high-T_c superconductor in…
Field distribution and flux-line depinning in the mixed-state of MgB2 probed by Conduction Electron Spin Resonance
R. R. Urbano, P. G. Pagliuso, C. Rettori +3
We report the first observation of the internal magnetic-field distribution and flux-line depinning in the vortex-state of a type-II superconductor probed by conduction electrons s…
Current-Induced Superconductor-Insulator Transition in Granular High-T_c Superconductors
Y. Kopelevich, C. A. M. dos Santos, S. Moehlecke +1
In this work we report a systematic study of electrical current effects on superconducting properties of granular YPrBaCuO samples with x close to…
Comment on ``New Vortex-Matter Size Effect Observed in BiSrCaCuO"
Y. Kopelevich, P. Esquinazi
The Letter of Wang et al. \cite{wan} is related to the recently discovered vanishing of the second magnetization peak (SMP) in high- superconductors reducing the sample size \…
Comment on "Quantum Melting of the Quasi-Two-Dimensional Vortex Lattice in "
Y. Kopelevich, P. Esquinazi
In a recent Letter Mola et al. \cite{mola} reported magnetization measurements performed on the organic superconductor (ET)Cu(NCS) K) as a function…
Indication of Superconductivity at 35 K in Graphite-Sulfur Composites
R. Ricardo da Silva, J. H. S. Torres, Y. Kopelevich
We report magnetization measurements performed on graphite--sulfur composites which demonstrate a clear superconducting behavior below the critical temperature T = 35 K. The…
Nonmonotonic Temperature Dependence of the Thermal Hall Angle of a YBaCuO Single Crystal
R. Ocaña, A. Taldenkov, P. Esquinazi +1
We have performed high-resolution measurements of the magnetic field (0~T~T) and temperature (10 K~K) dependence of the longitudinal and transverse Hal…