Related papers: Supercurrent on a vortex core in 2H-NbSe$_2$: curr…
The observation by scanning tunnelling spectroscopy (STS) of Abrikosov vortex cores in the high-temperature superconductor YBa$_2$Cu$_3$O$_{7-\delta}$ (Y123) has revealed a robust pair of electron-hole symmetric states at finite subgap…
The study of superconducting materials that also possess nontrivial correlations or interactions remains an active frontier of condensed matter physics. NbSe$_2$ belongs to this class of superconductors and recent research has focused on…
We present scanning tunneling microscopy and spectroscopy measurements at 100mK in the superconducting material 2H-NbSe2 that show well defined features in the superconducting density of states changing in a pattern closely following atomic…
The vortex dynamics in the spin-triplet superconductor, UTe$_2$, are studied by measuring the DC electrical resistivity with currents along the $a$-axis under magnetic fields along the $b$-axis. Surprisingly, we have discovered an island…
We investigate the relation of the critical current density (Jc) and the remarkably increased superconducting transition temperature (Tc) for the FeSe single crystals under pressures up to 2.43 GPa, where the Tc is increased by ~8 K/GPa.…
The superconducting upper critical field $H_{c2}(T)$ of a two dimensional BCS superconductor is calculated in the vicinity of a van-Hove singularity. The zero temperature upper critical field is strongly enhanced at weak coupling when the…
We study theoretically the effect of the fermion and boson densities on the superconductivity transition critical temperature $(T_c)$ of a two dimensional electron gas (2DEG), where superconductivity is mediated by a Bose-Einstein…
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…
We have measured the low temperature heat capacity Cp and microwave surface impedance Zs in the vortex state of YNi_2B_2C. In contrast to conventional s-wave superconductors, Cp shows a nearly \sqrt H-dependence. This \sqrt H-dependence…
In this paper we demonstrate how, using a natural generalization of BCS theory, superconducting phase coherence manifests itself in phase insensitive measurements, when there is a smooth evolution of the excitation gap \Delta from above to…
In the presence of an external magnetic field, the low lying elementary excitations of a d-wave superconductor have quantized energy and their momenta are locked near the node direction. It is argued that these discrete states can most…
Transport current distribution in clean 2$H$-NbSe$_{2}$ crystals is studied by measuring the self-induced magnetic field across the sample. Below $T_c$ most of the current flows at the edges of the crystals due to strong surface barriers,…
On the basis of the time-dependent Ginzburg-Landau equation we studied the dynamics of the superconducting condensate in a wide two-dimensional sample in the presence of a perpendicular magnetic field and applied current. We could identify…
We investigate the phenomenon of decay of a supercurrent in a superconducting thin film in the absence of an applied magnetic field. The resulting zero-temperature resistance derives from two equally possible mechanisms: 1) quantum…
Transverse ac permeability measurements in Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta }$ single crystals at low fields and temperatures in a vortex configuration free of external forces show that the decrease of the critical current as measured by…
Quasiparticle transport in the vortex state of an s-wave superconductor at T -> 0 was investigated by measuring the thermal conductivity of LuNi_2B_2C down to 70 mK in a magnetic field perpendicular to the heat current. In zero field, there…
The magnetic field dependence of the electronic specific heat C(H) in the s-wave superconductor NbSe_2 shows curvature at low fields, resembling the near H^1/2 term in C(H) which has been reported in high-T_c superconductors and attributed…
We study vortex current distributions in narrow thin-film superconducting strips. If one defines the vortex core ``boundary" as a curve where the current reaches the depairing value, intriguing features emerge. Our conclusions based on the…
There are several ways to turn a superconductor into a normal conductor: increase the temperature, apply a high magnetic field, or run a large current. High-T$_c$ cuprate superconductors are unusual in the sense that experiments suggest…
The coherent mixing of the current states in the superconducting weak link subject to a Josephson phase difference $\phi$ and subject to an external transport current in the banks is one of the aims of this work. At $\phi=\pi $ the nonlocal…