相关论文: Geometric effects on T-breaking in p+ip and d+id s…
It is argued that recent Josephson junction and point-contact tunneling experiments, interpreted as intended by their authors, indicate that time-reversal symmetry breaking occurs at surfaces of cuprate superconductors. The variation among…
Time-reversal symmetry breaking superconductivity is a quintessential unconventional quantum state. In Josephson junctions, time-reversal symmetry breaking manifests itself in the supercurrent interference pattern as the invariance of the…
We consider different effects that arise when time-reversal symmetry breaking superconductors are subjected to an external magnetic field, thus rendering the superconductor to be in the mixed state. We focus in particular on two…
Spontaneous time-reversal symmetry breaking in superconductors with competing non-degenerate pairing channels is an exotic quantum phase transition that could give rise to robust topological superconductivity and unusual magnetism. It is…
We model the Fermi surface of the cuprates by one-dimensional nested parts near $(0,\pi)$ and $(\pi,0)$ and unnested parts near the zone diagonals. Fermions in the nested regions form 1D spin liquids, and develop spectral gaps below some…
We propose and implement a direct experimental test for subdominant superconducting phases with broken time-reversal symmetry in d-wave superconductors. The critical current of 45-degree asymmetric grain boundary junctions are shown to be…
Recently, Kaminski et al. have reported that time reversal symmetry is broken in the pseudogap phase in the high temperature superconducting material Bi_2Sr_2CaCu_2O_{2+\delta} (Bi-2212). Here we examine the role of translationally…
We argue that a locally time-reversal symmetry breaking state can occur at Josephson junctions between unconventional superconductors. Order parameters induced by the proximity effect can combine with the bulk order parameter to form such a…
In this paper we study the order parameter and density of states near a grain boundary between two $d_{x^2-y^2}$ superconductors. We examine broken time reversal symmetry near the interface. In particular we show that, under suitable…
Junctions and interfaces consisting of unconventional superconductors provide an excellent experimental playground to study exotic phenomena related to the phase of the order parameter. Not only the complex structure of unconventional order…
Spontaneous time-reversal symmetry breaking plays an important role in studying strongly correlated unconventional superconductors. When two superconducting gap functions with different symmetries compete, the relative phase channel…
A model system consisting of a mesoscopic superconducting grain coupled by Josephson junctions to two macroscopic superconducting electrodes is studied. We focus on the effects of ohmic dissipation caused by resistive shunts and…
We consider a model of multiband superconductivity, inspired by iron pnictides, in which three bands are connected via repulsive pair-scattering terms. Generically, three distinct superconducting states arise within such a model. Two of…
We consider nonreciprocal supercurrent effects in Josephson junctions based on multiband superconductors with a pairing structure that can break time-reversal symmetry. We demonstrate that a nonreciprocal supercurrent can be generally…
We study time reversal symmetry breaking superconductivity with $\Delta_k = \Delta_{x^2-y^2} (k) +e^{i\theta} \Delta_{\alpha}$ ($\alpha = s$ or $d_{xy}$) symmetries. It is shown that the behavior of such superconductors could be {\em…
The s+- state in which order parameter has different signs in different bands is a leading candidate for the superconducting state in the iron based superconductors. We investigate a Josephson junction between s and s+- superconductors…
We study the order parameter symmetry in bi-layer cuprates such as YBaCuO, where interesting $\pi$ phase shifts have been observed in Josephson junctions. Taking models which represent the measured spin fluctuation spectra of this cuprate,…
We consider a renormalization group study of the problem of coupled stripes of holes in cuprates. We use a model of a mesh of horizontal and vertical stripes and study the problemof superconductivity via the Josephson coupling. We discuss…
We study spontaneous time-reversal symmetry breaking at Josephson tunnel junctions of d-wave superconductors in the absence of subdominant components of the order parameter. For tunnel junctions, when the orientation is close to 0/45 (for…
We review and extend a previous study on the symmetry of the superconducting state, stimulated by recent tunneling and Andreev reflection measurements giving robust evidences for the existence of a $d_{x^2-y^2}+id_{xy}$ order parameter in…