相关论文: Tunneling spectroscopy of $s\pi$ pairing state as …
In this paper we present scanning tunneling microscopy of a large $\textrm{Bi}_2\textrm{Se}_3$ crystal with superconducting PbBi islands deposited on the surface. Local density of states measurements are consistent with induced…
The smooth evolution of the tunneling gap of Bi_2Sr_2CaCu_2O_8 with doping from a pseudogap state in the underdoped cuprates to a superconducting state at optimal and overdoping, has been interpreted as evidence that the pseudogap must be…
The electronic states of surface adatoms in Na(Fe0.96Co0.03Mn0.01)As have been studied by low temperature scanning tunneling spectroscopy. The spectra recorded on the adatoms display both superconducting coherence peaks and an asymmetric…
We present extensive Scanning Tunneling Spectroscopy (STM/S) measurements at low temperatures in the multiband superconductor MgB$_2$. We find a similar behavior in single crystalline samples and in single grains, which clearly shows the…
We report the results of a study of superconducting proximity effects in clean Ferromagnet/Ferromagnet/Superconductor (${\rm F_1F_2S}$) heterostructures, where the pairing state in S is a conventional singlet s-wave. We numerically find the…
In s-wave superconductors the Cooper pair wave function is isotropic in momentum space. This property may also be expected for Cooper pairs entering a normal metal from a superconductor due to the proximity effect. We show, however, that…
We suggest a mechanism which promotes the existence of a phase soliton -- topological defect formed in the relative phase of superconducting gaps of a two-band superconductor with s+- type of pairing. This mechanism exploits the proximity…
The optical conductivity of Ba(Fe$_{0.92}$Co$_{0.08}$)$_2$As$_2$ shows a clear signature of the superconducting gap, but a simple $s$-wave description fails in accounting for the low frequency response. This task is achieved by introducing…
Planar tunneling junctions of the presumably unconventional superconductor FeSe were prepared and investigated. The junctions consisted of FeSe/AlOx/Ag multilayers patterned lithographically into mesa structures. Bias voltage dependent…
We investigate the conductance through and the spectrum of ballistic chaotic quantum dots attached to two s-wave superconductors, as a function of the phase difference $\phi$ between the two order parameters. A combination of analytical…
We consider a Josephson junction bilayer consisting of two tunnel-coupled two-dimensional electron gas layers with Rashba spin-orbit interaction, proximitized by a top and bottom $s$-wave superconductor with phase difference $\phi$ close to…
High-resolution angle-resolved photoemission measurements were taken on FeSe$_{1-x}$S$_x$ (x=0, 0.04, and 0.08) superconductors. With an ultrahigh energy resolution of 0.4 meV, unusual two hole bands near the Brillouin-zone center, which…
We study a diagonal 2-orbital ladder model of the Fe based superconductors using the density matrix renormalization group method. At half filling, we find a close competition between a "spin-striped" state and a non-collinear…
A novel state is predicted for a S/F heterostructure. It is shown that the equilibrium F/S bilayer can be in a bistable state: one state is ground and the other is metastable. One of these states is always normal and the other is…
In unconventional superconductors, it is generally believed that understanding the physical properties of the normal state is a pre-requisite for understanding the superconductivity mechanism. In conventional superconductors like niobium or…
The density of states modulation recently observed by the scanning tunneling microscopic experiment in the pseudogap state of high-$T_c$ superconductors is explained by the pairing assisted particle transitions under perturbation of a…
The de Gennes extrapolation length is a direction dependent measure of the spatial evolution of the pairing gap near the boundary of a superconductor, and thus provides a viable means to probe its symmetry. It is expected to be infinite and…
We study the proximity-induced superconducting state in a general bilayer -- conventional $s$-wave superconductor hybrid structure. For the bilayer we include a general parabolic dispersion, Rashba spin-orbit coupling, and finite layer…
Using a prototype model for proximity induced superconductivity on a bilayer square lattice, we show that interlayer tunneling can drive change in topology of the Bogoliubov quasiparticle bands. Starting with topologically trivial…
Under certain conditions, the order parameter induced by a superconductor (S) in a ferromagnet (F) can be inhomogeneous and oscillating, which results e.g. in the so-called pi-coupling in S/F/S junctions. In principle, the inhomogeneous…