Two-dimensional fluctuations in the magnetization ofBi2Sr2

Low temperature fluctuations of vortices in layered superconductors

“…This has been observed in "non-mean-field" dependence of the magnetization M on temperature T and magnetic field H in Bi 2 Sr 2 CaCu 2 0 8 (Bi-2212) and Bi 2 Sr2Ca 2 Cu30io (Bi-2223) well under the mean-field transition temperature T C Q. At a temperature T*, a few kelvins below T c o, M is field independent [1][2][3], The effect has been explained quantitatively by the contribution of fluctuating vortices to the system entropy [4].…”

“…The order parameter modulus of superconducting layers was set constant in space and time (at T's not too close to T c o) while vortex positions (i.e., phases) were fluctuating [5]. As such the method is not restricted to high temperatures although, at first sight, there is no reason to test the effect of fluctuations at low T. Indeed, as follows from the data [1][2][3], the fluctuation contribution to the free energy is on the order of the mean-field free energy near T*, which is not far from T c0 ; with decreasing T, the unperturbed energy increases (in absolute value) while the fluctuation part diminishes.…”

Three-dimensional superconducting behavior and thermodynamic parameters ofHgBa2Ca0.86Kim1, Lee2, Sui3 et al. 1996Phys. Rev. B302170View full textAdd to dashboardCite

“…͑4͒ without the ln factor, i.e., ln(␣/ͱe) ϭ 1. Several groups have shown that the R is the same as the distance s between two adjacent CuO 2 blocks for a 2D system such as Bi-2212, Bi 2 Sr 2 Ca 2 Cu 3 O 10 ͑Bi-2223͒, 15,16 and PrCeCuO ͑Ref. 17͒ compounds.…”

Anisotropy and reversible magnetization of the infinite-layer superconductorSr0.9La0.1CuOKim1, Lemberger2, Jung3 et al. 2002Phys. Rev. B29391View full textAdd to dashboardCite

“…2 However, the 3D region for strongly anisotropic compounds, such as Bi-based superconductors, is found to be extremely narrow. 3 The infinite-layer superconductors ͑ILS͒ have attracted much attention due to their simple structure: infinite stacking of CuO 2 planes separated only by alkaline earth ions. 4 -9 Since the unit cell of an infinite-layer superconductor does not have a charge reservoir block ͑CRB͒, such as a rock-saltor a fluoritelike block in usual high-T c superconductors, the distance between CuO 2 planes is the shortest among the cuprates.…”