Boundary conditions in quasiclassical theory of superconductivity are of crucial importance for describing proximity effects in heterostructures between differentmaterials. Although they have been derived for the ballistic case in full generality, corresponding boundary conditions for the diffusive limit, described byUsadel theory, have been lacking for interfaces involving strongly spin-polari...

The effect of cooling process for the synthesis and the superconductivity properties of Pb-substituted Bi-based materials, has been investigated. The preparation condition for the formation of (2,2,2,3) phase has been examined. The influence of thermal condition of the synthesis and quenching on the critical temperature and the content of 110K phase was investigated. Results of the ac-susceptib...

We argue that recent neutron scattering measurements by Lake et al. [Science 291, 1759 (2001)] of the spin excitation spectrum of La(2-delta)Sr(delta)CuO4 in a magnetic field can be understood in terms of proximity to a phase with co-existing superconductivity and spin density wave order. We present a general theory for such quantum transitions, and argue that their low energy spin fluctuations...

The two-dimensional Hubbard model exhibits superconductivity with d-wave symmetry even at half-filling in the presence of a next-nearest neighbor hopping. Using plaquette cluster dynamical mean-field theory with a continuous-time quantum Monte Carlo impurity solver, we reveal the non-Fermi liquid character of the metallic phase in proximity to the superconducting state. Specifically, the low-fr...

The Fermi surface of most hole-doped cuprates is close to a Van Hove singularity at the M point. A two-dimensional electronic system, whose Fermi surface is close to a Van Hove singularity, shows a variety of weak coupling instabilities. It is a convenient model to study the interplay between antiferromagnetism and anisotropic superconductivity. The renormalization group approach is reviewed wi...

– We performed the local spectroscopy of a Normal-metal–Superconductor (N-S) junction with the help of a very low temperature (60 mK) Scanning Tunneling Microscope (STM). The spatial dependence of the local density of states was probed locally in the vicinity of the N-S interface. We observed spectra with a fully-developed gap in the regions where a thin normal metal layer caps the superconduct...

Majorana bound states are zero-energy predicted to emerge in topological superconductors and intense efforts seeking definitive proof of their observation still ongoing. A standard route realize them involves antagonistic orders: a superconductor proximity ferromagnet. Here, we show that this issue can be resolved using antiferromagnetic rather than ferromagnetic order. We propose use chain sky...

We report a non-magnetic impurity effect on the superconductivity observed in (TMTSF)2ClO4. By varying the sample cooling rate in the vicinity of an anion ordering transition at TAO = 24 K, we can systematically control the amount of disorder in the sample. We then use dc transport and microwave periodic orbit resonance measurements (closely related to cyclotron resonance) to determine the crit...

Recent experimental discovery of flavor symmetry breaking metallic phases in Bernal-stacked bilayer graphene points to the strongly interacting nature electrons near top (bottom) its valence (conduction) band. Superconductivity was also observed between these when is placed under a small in-plane magnetic field or close proximity monolayer WSe$_2$ substrate. Here we address correlated band edge...

We experimentally investigate the magnetic field dependence of Andreev transport through a region proximity-induced superconductivity in CoSi topological chiral semimetal. With increasing parallel to surface, sharp subgap peaks, associated with bound states, move together nearly-zero bias position, while there is only monotonic peaks suppression for normal surface fields. The zero-bias $$dV{\te...