Related papers: Vortex lattice disorder in YBCO probed using Beta-…

We report on simulations of layered superconductors using the Lawrence-Doniach model in the framework of the lowest Landau level approximation. We find a first order phase transition with a $B(T)$ dependence which agrees very well with the…

The vortex-lattice melting transitions in two typical iron-based high-Tc superconductor $Ba(Fe_{1-x}Co_{x})_{2}As_{2}$ (122-type) and$Nd(O_{1-x}F_{x})FeAs$ (1111-type) for magnetic fields both parallel and perpendicular to the anisotropy…

We report a $^{11}$B NMR line shape and spin-lattice relaxation rate ($1/(T_1T)$) study of pure and lightly carbon doped MgB$_{2-x}$C$_{x}$ for $x=0$, 0.02, and 0.04, in the vortex state and in magnetic field of 23.5 kOe. We show that while…

Longitudinal and Hall voltages are measured in a clean twinned YBCO single crystal in the liquid and solid vortex phases. For magnetic fields tilted away from the c-axis more than about 2 deg, a scaling law |rho_xy|=A (rho_xx)^beta with…

The work presented in my doctoral thesis is an experimental investigation of the nature of order to disorder transition of vortex lattice in a Type-II superconductor namely Co-intercalated 2H-NbSe2 using scanning tunnelling spectroscopy and…

Vortices in superconductors can help identify emergent phenomena but certain fundamental aspects of vortices, such as their entropy, remain poorly understood. Here, we study the vortex entropy in underdoped Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ by…

We have studied two nanomagnet systems with strong (Co/Pd multilayers) and weak (NdCo alloy films) stray magnetic fields by probing the out-of-plane magnetic states with superconducting vortices. The hybrid samples are made of array of…

We report a direct observation of the magnetic vortex lattice in the model high-temperature superconductor HgBa2CuO4+x. Using small-angle neutron scattering on high-quality crystals, we observe two equal domains of undistorted triangular…

The temperature dependence of the site-dependent nuclear spin relaxation time T_1 around vortices is studied in s-wave and d-wave superconductors.Reflecting low energy electronic excitations associated with the vortex core, temperature…

This is the first report of the observation of the onset of excess volume and also of the strain along the a-axis near the magnetic ordering temperature in Ru-1222 superconductor, and indicates a coupling between the lattice and the…

A 2-Q antiferromagnetic order of the ferromagnetic dimers was found below TN = 2.9 K in the Shastry-Sutherland lattice BaNd2ZnS5 by single crystal neutron diffraction. The magnetic order can be understood by the orthogonal arrangement of…

An advanced mask-less nanofabrication technique, focused electron beam-induced deposition (FEBID), has been employed on epitaxial Nb thin films for their ferromagnetic decoration by an array of Co stripes. These substantially modify the…

Flux line lattice in type II superconductors undergoes a transition into a "disordered" phase like vortex liquid or vortex glass, due to thermal fluctuations and random quenched disorder. We quantitatively describe the competition between…

The magnetic resonance at 41 meV observed in neutron scattering studies of Y Ba_2 Cu_3 O_7 holds a key position in the understanding of high-T_c superconductivity. Within the SO(5) model for superconductivity and antiferromagnetism, we have…

Using the small angle neutron scattering (SANS) technique we investigated the vortex lattice (VL) in the mixed state of the stannide superconductor Yb$_{3}$Rh$_{4}$Sn$_{13}$. We find a single domain VL of slightly distorted hexagonal…

Magnetization and 63Cu NMR-NQR relaxation measurements are used to study the superconducting fluctuations in YBa2Cu3O6+x (YBCO) oriented powders. In optimally doped YBCO the fluctuating negative magnetization M_{fl}(H,T) is rather well…

Using electron spin resonance (ESR) technique we have obtained data evidencing the existence of magnetic vortices in high-temperature superconductors at temperatures above the critical one $T_c$. We have studied magnetic excitations in \bis…

Using dynamic cantilever magnetometry, we study the vortex lattice and its corresponding melting transition in a micrometer-size crystallite of superconducting NbSe2. Measurements of the cantilever resonance frequency as a function of…

We study the interplay between magnetism and superconductivity in high quality YBa2Cu3O7 (YBCO) / La0.7Ca0.3MnO3(LCMO)superlattices. We find evidence for the YBCO superconductivity depression in presence of the LCMO layers. We show that due…

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…