Related papers: Diamagnetism and Cooper pairing above $T_c$ in cup…
In hole-doped cuprates, Nernst experiments imply that the superconducting state is destroyed by spontaneous creation of vortices which destroy phase coherence. Using torque magnetometry on $\rm Bi_2Sr_2CaCu_2O_{8+\delta}$, we uncover a…
Nernst and magnetization experiments reveal the existence of a large region of the cuprate phase diagram above the $T_c$ curve in which vorticity and weak diamagnetism exist without phase coherence. We discuss the implication that the…
Various superconductors, including cuprate superconductors, exhibit peculiar features above the transition temperature T_c. In particular the observation of a large diamagnetism and Nernst signal in a wide temperature window above T_c…
When a superconductor is warmed above its critical temperature $T_c$, long range order is destroyed by fluctuations in the order parameter. These fluctuations can be probed by measurements of conductivity, diamagnetism, and of the Nernst…
The diffusion of vortices down a thermal gradient produces a Josephson signal which is detected as the vortex Nernst effect. In a recent report, Xu et al., Nature 406, 486 (2000), an enhanced Nernst signal identified with vortex-like…
There is strong evidence that magnetic interactions play a crucial role in the mechanism driving high-temperature superconductivity in cuprate superconductors. To investigate this further we have done neutron scattering experiments on the…
In this brief report an attempt is made for a 'mise-a-point' of the subject of the phase fluctuations of the superconducting order parameter above Tc in cuprates, particularly as they appear in underdoped compounds. Measurements of torque…
Superconductivity in the cuprates emerges from an enigmatic metallic state. There remain profound open questions regarding the universality of observed phenomena and the character of precursor fluctuations above the superconducting (SC)…
Normal state orbital diamagnetism of charged bosons quantitatively accounts for recent high-resolution magnetometery results near and above the resistive critical temperature Tc of superconducting cuprates. Our parameter-free descriptions…
We address those puzzling experiments in underdoped high $T_c$ superconductors which have been associated with normal state "vortices" and show these data can be understood as deriving from preformed pairs with onset temperature $T^* >…
Linear diamagnetism is predicted in the vortex-liquid phase of layered superconductors at temperatures just below the mean-field phase transition on the basis of a high-temperature analysis of the corresponding frustrated XY model. The…
By using thermal and Lorentz force, the vortex motion is successfully manipulated in the mixed state of underdoped La$_{2 - x}$Sr$_{x}$CuO$_{4}$ single crystals and optimally doped YBa$_{2}$Cu$_{3}$O$_{7 - \delta}$ thin films. A conclusion…
The observation of a large Nernst signal $e_N$ in an extended region above the critical temperature $T_c$ in hole-doped cuprates provides evidence that vortex excitations survive above $T_c$. The results support the scenario that…
It is often claimed that among the strongest evidence for preformed-pair physics in the cuprates are the experimentally observed large values for the diamagnetic susceptibility and Nernst coefficient. These findings are most apparent in the…
Recently experiments on high critical temperature superconductors has shown that the doping levels and the superconducting gap are usually not uniform properties but strongly dependent on their positions inside a given sample. Local…
In order to investigate the inhomogeneity of the superconducting (SC) state in the overdoped high-$T_{\rm c}$ cuprates, we have measured the magnetic susceptibility, $\chi$, of La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) single crystals in the overdoped…
We present a study of Nernst effect in underdoped $La_{2-x}Sr_xCuO_4$ in magnetic fields as high as 28T. At high fields, a sizeable Nernst signal was found to persist in presence of a field-induced non-metallic resistivity. By…
We report here a comprehensive study on structural, magnetic, caloric and electronic properties of the monoclinic phase of double perovskite compound Tm2CoMnO6 (TCMO) in its polycrysttaline format. Magnetic measurements confirm the presence…
We use the Nernst effect to delineate the boundary of the pseudogap phase in the temperature-doping phase diagram of cuprate superconductors. New data for the Nernst coefficient $\nu(T)$ of YBa$_{2}$Cu$_{3}$O$_{y}$ (YBCO),…
The in-plane $\rho_{ab}(H,T)$ and the out-of-plane $\rho_c(H,T)$ magneto-transport in magnetic fields up to 28 T has been investigated in high quality non-superconducting (down to 20 mK) La-free Bi$_{2+x}$Sr$_{2-x}$CuO$_{6+\delta}$ single…