The helicity modulus for a fluctuating type II superconductor is computed within the elastic medium approximation, as a probe of superconducting phase coherence and the Meissner effect in the mixed state. We argue that at the vortex line lattice melting transition, there remains superconducting coherence parallel to the applied magnetic field, provided the vortex line liquid retains a finite sh...

Spin fluctuations are a leading candidate for the pairing mechanism in high temperature superconductors, supported by the common appearance of a distinct resonance in the spin susceptibility across the cuprates, iron-based superconductors and many heavy fermion materials. The information we have about the spin resonance comes almost exclusively from neutron scattering. Here we demonstrate that ...

In multi-band metals quasi-particles arising from different atomic orbitals coexist at a common Fermi surface. Superconductivity in these materials may appear due to interactions within a band (intra-band) or among the distinct metallic bands (inter-band). Here we consider the suppression of superconductivity in the intra-band case due to hybridization. The fluctuations at the superconducting q...

To investigate the static and dynamic magnetic properties on uranium-based superconductor UTe$_{2}$, we measured NMR Knight shift $K$ nuclear spin-lattice relaxation rate $1/T_{1}$ in $H \parallel a$ by $^{125}$Te-NMR a $^{125}$Te-enriched single-crystal sample. $1/T_1T$ is much smaller than b$ $c$, fluctuations along each axis are derived from $H$ parallel to all three crystalline axes. The al...

Motivated by a mean field-like resistive behavior in magnetic fields commonly seen in various superconducting cuprates and organics with strong fluctuation, superconducting (SC) quantum fluctuation effects on resistive behaviors are reexamined by putting emphasis on their roles in the so-called thermal vortex liquid regime. By incorporating the quantum fluctuations and a vortex pinning effect i...

superconductor fault current limiter (sfcl) is an effective device to suppress high fault currents. this paper presents a comparative study of resistive and inductive fault current limiters from transient stability point of view.  appropriate location and type of the limiters in a hv substation is selected by a qualitative approach based on the equal area criterion. study system is simulated by...

Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. In 2 þ 1 dimensions at finite temperature, spontaneous symmetry breaking of global symmetries is precluded by large...

Since their discovery, it has been suggested that pairing in pnictides can be mediated by spin fluctuations between hole and electron bands. In this view, multiband superconductivity would substantially differ from other systems like MgB2, where pairing is predominantly intraband. Indeed, interband-dominated pairing leads to the coexistence of bonding and antibonding superconducting channels. H...

We report polarized neutron scattering measurements of the low energy spin fluctuations iron-selenide superconductor Li$_{0.8}$Fe$_{0.2}$ODFeSe below and above its superconducting transition temperature $T_c=41$ K. Our experiments confirmed that resonance mode near 21 meV is magnetic. Moreover, excitations are essentially isotropic in space at 5$\leq E\leq$ 29 normal states. results suggest iro...

In most superconductors electrons form Cooper pairs in a spin-singlet state mediated by either phonons or long-range interactions such as spin fluctuations. The superconductor UTe$_2$ is rare material wherein are believed to unique spin-triplet with potential topological properties. While pairing may be ferromagnetic antiferromagnetic fluctuations, experimentally, the magnetic properties of unc...