Related papers: Subharmonic gap structure in d-wave superconductor…
In scanning tunneling microscopy (STM) conductance curves, the superconducting gap of cuprates is sometimes accompanied by small sub-gap structures at very low energy. This was documented early on near vortex cores and later at zero…
We investigate the properties of subharmonic gap structure (SGS) in superconducting quantum contacts with normal-electron resonances. We find two distinct new features of the SGS in resonant junctions which distinguish them from…
The current-voltage characteristics of Josephson junctions exhibit a subharmonic gap structure (SGS), denoting jumps at specific voltages. While the prevalent multiple Andreev reflection theory matches the experimentally observed SGS, it is…
The issue of probing the pseudogap regime of the cuprate superconductors, specifically with regard to the existence and nature of superconducting pairing correlations of d-wave symmetry, is explored theoretically. It is shown that if the…
The formation of bound states at surfaces of materials with an energy gap in the bulk electron spectrum is a well known physical phenomenon. At superconductor surfaces, quasiparticles with energies inside the superconducting gap $\Delta$…
We investigate the dc current-voltage characteristics of d-wave Josephson junctions, where the barrier at the interface may have arbitrary strength. Dividing the current into n-particle currents $I_n$ (n integer), we can explicitly show…
A boundary between two d-wave superconductors or an s-wave and a d-wave superconductor generally breaks time-reversal symmetry and can generate spontaneous currents due to proximity effect. On the other hand, surfaces and interfaces in…
Scanning tunneling spectroscopy experiments on a number of cuprate superconductors have revealed that these materials are highly inhomogeneous. However, even though this inhomogeneity is well-characterized experimentally, a theoretical…
To understand the interplay of d-wave superconductivity and antiferromagnetism in the cuprates, we consider a two-dimensional extended Hubbard model with nearest neighbor attractive interaction. Free energy of the homogeneous (coexisting…
We study the emergence of multiband superconductivity with $s$- and $d-$wave symmetry on the background of spin density wave (SDW). We show that the SDW coherence factors renormalize the momentum dependence of the superconducting (SC) gap,…
We investigate the vortex structure assuming the d-density wave scenario of the pseudogap. We discuss the profiles of the order parameters in the vicinity of the vortex, effective vortex charge and the local density of states. We find a…
We present a theoretical analysis of the current-voltage characteristics of a ballistic superconductor-normal-superconductor (SNS) junction, in which a strip of graphene is coupled to two superconducting electrodes. We focus in the…
Superconducting mechanism of cuprates is discussed in the light of the proximity of the Mott insulator. The proximity accompanied by suppression of coherence takes place in an inhomogeneous way in the momentum space in finite-dimensional…
We observe a subharmonic gap sturucture (SGS) and the Josephson effect in superconducting scanning tunneling microscope junctions with resistances below 100 kOhm. The magnitude of the n=2 SGS is shown to scale with the square of the…
We derive a pair potential from tight binding further neighbours attraction that leads to superconducting gap symmetry similar to that of the phenomenological spin fluctuation theory of high temperature superconductors (Monthoux, Balatsky,…
The behavior of dc subgap current in magnetic quantum point contact is discussed for the case of low-transparency junction with different tunnel probabilities for spin-up ($D_\uparrow$) and spin-down ($D_\downarrow$) electrons. Due to the…
The evidence for the spin density wave (SDW) nature of the pseudogap in HTSC cuprates is presented from resistive and direct gap measurements (ARPES, tunneling experiments, etc.). Its d-wave symmetry mimics the symmetry of the order…
We analyze the influence of the structure within a SNS junction on the multiple Andreev resonances in the subgap I-V characteristics. Coherent interference processes and incoherent propagation in the normal region are considered. The…
We demonstrate how potential impurities are a very powerful tool for determining the pairing symmetry in graphene proximity-coupled to a spin-singlet superconductor. All d-wave states are characterized by subgap resonances, with spatial…
Impurities in superconductors and their induced bound states are important both for engineering novel states such as Majorana zero-energy modes and for probing bulk properties of the superconducting state. The high-temperature cuprates…