相关论文: Thermally induced gaplessness and Fermi arcs in a …
We explore multiband effects on d-wave superconducting instabilities driven by electron-electron interactions. Our models on the two-dimensional square lattice consist of a main band with an extended Fermi surface and predominant weight…
We study the pairing instability of a two-dimensional metallic system induced by Ising-nematic quantum fluctuations in the presence of an unavoidable relevant coupling of the nematic order parameter to the elastic modes (acoustic phonons)…
The underlying physics of the magnetic-field-induced resistive state in high temperature cuprate superconductors remains a mystery. One interpretation is that the application of magnetic field destroys the d-wave superconducting gap to…
The low-temperature thermal conductivity \kappa_0/T of d-wave superconductors is generally thought to attain a "universal" value independent of disorder at sufficiently low temperatures, providing an important measure of the magnitude of…
We investigate the universal electronic transport for a mixed $d_{x^2-y^2}$+s-wave superconductor in the presence of an anisotropic elliptical Fermi surface. Similar to the universal low-temperature transport predicted in a…
Superconductivity and magnetic order strongly compete in many conventional superconductors, at least partly because both tend to gap the Fermi surface. In magnetically-ordered conventional superconductors, the competition between these…
The comprehensive low-temperature specific heat C(T) data identify both an isotropic s-wave and an extended s-wave order parameters coexisting in a superconducting single crystal FeSe with Tc=8.11 K. The isotropic gap {\Delta}0=1.33 meV on…
We present a strong coupling dynamical theory of the superconducting transition in a metal near a QCP towards $Q = 0$ nematic order. We use a fermion-boson model, in which we treat the ratio of effective boson-fermion coupling and the Fermi…
Competition between superconductivity and disorder plays an essential role in understanding the metal-insulator transition. Based on the Bogoliubov-de Gennes equation, we studied an s-wave superconductor with both spin-orbit coupling and…
We investigate the pairing in iron pnictides in the coexistence phase, which displays both superconducting and antiferromagnetic orders. By solving the pairing problem on the Fermi surface reconstructed by long-range magnetic order, we find…
Based on experimental results and our previous theoretical work, a microscopic theory of high temperature superconductivity is conjectured. In this conjecture, superconducting and antiferromagnetic long-range orders are driven by interlayer…
Magnetic properties under the external field are investigated in low-carrier two-band systems, which may explain the nontrivial phase boundary found in temperature vs. magnetic field diagram discovered in some materials, such as…
We report electronic Raman scattering measurements of Sr(Fe$_{1-x}$Co$_x$)$_2$As$_2$ single crystals in their magnetic - Spin Density Wave (SDW) phase. The spectra display multiple, polarization-resolved SDW gaps as expected in a…
We study the effects of an external magnetic field on the superconducting properties of a quasi-two-dimensional system of Dirac electrons at an arbitrary temperature. An explicit expression for the superconducting gap is obtained as a…
The symmetry of superconductivity in borocarbides LuNi2B2C and YNi2B2C is an outstanding issue. Here an anisotropic s- wave order parameter (or s+g model) is proposed for these borocarbides. In spite of the dominant s- wave component the…
Superconductivity in strongly correlated systems is a remarkable phenomenon that attracts a huge interest. The study of this problem is relevant for materials as the high Tc oxides, pnictides and heavy fermions. In this work we study a…
The recent discovery of superconductivity in iron-arsenic compounds below a transition temperature (Tc) as high as 55K ended the monopoly of copper oxides (cuprates) in the family of high-Tc superconductors. A critical issue in…
We study SU(4)-symmetric ultracold fermionic mixture in the cubic optical lattice with the variable tunneling amplitude along one particular crystallographic axis in the crossover region from the two- to three-dimensional spatial geometry.…
The temperature and frequency dependences of the conductivity are derived from optical reflection and transmission measurements of electron doped BaFe$_2$As$_2$ crystals and films. The data is consistent with gap nodes or possibly a very…
In the model considered, the nonlocal interaction of the fermions in different sublattices of a bipartite lattice is introduced. It can also be regarded as local interaction of fermions with opposite ``hypercharge''. The corresponding term…