Related papers: Supercurrent on a vortex core in 2H-NbSe$_2$: curr…
We calculated the electronic structure of a vortex in a pseudogapped superconductor within a model featuring strong correlations. With increasing strength of the correlations, the BCS core states are suppressed and the spectra in and…
In a Type II superconductor, the vortex core behaves like a normal metal. Consequently, the single-particle density of states in the vortex core of a conventional Type II superconductor remains either flat or (for very clean single…
It is well known that superconductivity in thin films is generally suppressed with decreasing thickness. This suppression is normally governed by either disorder-induced localization of Cooper pairs, weakening of Coulomb screening, or…
We investigated vortex dynamics in a single-crystal sample of type-II superconductor NbSe$_{2}$ using scanning tunneling microscopy at 4.2 K. The decay of the magnetic field at a few nT/s in our superconducting magnet induced the…
Order-disorder transitions take place in many physical systems, but observing them in detail in real materials is difficult. In two- or quasi-two-dimensional systems, the transition has been studied by computer simulations and…
We report on the observation of two types of current driven transitions in metastable vortex lattices. The metastable states, which are missed in usual slow transport measurements, are detected with a fast transport technique in the vortex…
We present a method to produce superconducting tips to be used in Scanning Tunneling Microscopy/Spectroscopy experiments. We use these tips to investigate the evolution of the electronic density of states of NbSe2 from 0.3K up to its…
Besides its fundamental interest, understanding the dynamics of pair breaking in superconducting nanostructures is a central issue to optimize the performances of superconducting devices such as qubits or photon detectors. However, despite…
We study the superconducting density of states and vortex lattice of single crystals of CaKFe$_4$As$_4$ using a scanning tunneling microscope (STM). This material has a critical temperature of $T_c= 35\,$ K, which is one of the highest…
One of the most promising routes for achieving unprecedentedly high critical currents in superconductors is to incorporate dispersed, non-superconducting nanoparticles to control the dissipative motion of vortices. However, these inclusions…
Most superconducting materials exhibit a vanishing density of states at the Fermi level and Anderson's theorem posits that the superconducting gap is robust against nonmagnetic disorder. Although dilute magnetic impurities lead to localized…
We report on critical currents and voltage noise measurements in Niobium strips in the superconducting state, in the presence of a bulk vortex lattice ($B < B_{C2}$) and in the surface superconducting state ($B_{c2}< B < B_{C3}$). For…
We report the direct observation in real space of the charge density wave (CDW) phase transition in pristine 2H-NbSe2 using atomic-resolution scanning tunneling microscopy (STM). We find that static CDW order is established in nanoscale…
Self-field imaging of current distribution in Ba0.6K0.4Fe2As2 superconductor is used to study the effect of drive on the low-field vortex solid to liquid melting phase transformation. At low fields, the current induced drive on the vortices…
Vortex mass in Fermi superfluids and superconductors and its influence on quantum tunneling of vortices are discussed. The vortex mass is essentially enhanced due to the fermion zero modes in the core of the vortex: the bound states of the…
Competition with magnetism is at the heart of high temperature superconductivity, most intensely felt near a vortex core. To investigate vortex magnetism we have developed a spatially resolved probe using nuclear magnetic resonance. Our…
We examine possibility of enhancement of superconductive critical temperature in two-dimensions. The weak coupling BCS theory is applied, especially when the Fermi level is near the edges of the electronic bands. The attractive interaction…
As superconductors are thinned down to the 2D limit, their critical temperature $T_c$ typically decreases. Here we report the opposite behavior, a substantial enhancement of $T_c$ with decreasing thickness, in 2D crystalline superconductor…
We calculate the Nernst effect in the vortex fluid phase, which occurs in the lower-T portion of the pseudogap region of the high Tc cuprate phase diagram. The dynamics is dominated by the flows due to both thermally excited vortices and…
Non-linear electrical transport studies at high-pulsed magnetic fields, above the range accessible by DC magnets, are of direct fundamental relevance to the physics of superconductors, domain-wall, charge-density waves, and topological…