Related papers: Anisotropic zero-resistance onset in organic super…
The superconducting transition in the layered organic compound \alpha-(BEDT-TTF)_2KHg(SCN)_4 has been studied in the two hydrostatic pressure regimes where a charge-density wave is either present or completely suppressed. Within the…
We explore if the phase separation or coexistence of the spin density wave (SDW) and superconductivity (SC) states has any relation to the incommensurability of the SDW in the Fe pnictide superconductors. A systematic method of determining…
Motivated by the recent discovery of a low temperature spin liquid phase in layered organic compound $\kappa$-(ET)$_2$Cu$_2$(CN)$_3$ which becomes a superconductor under pressure, we examine the phase transition of Mott insulating and…
The study of the anion ordered (TMTSF)\_2ClO\_4\_(1-x)ReO\_4\_x, solid solution in the limit of a low ReO\_4- substitution level (0<=x<=17%) has revealed a new and interesting phase diagram. Superconductivity is drastically suppressed as…
A linear temperature dependence of the electrical resistivity as T -> 0 is the hallmark of quantum criticality in heavy-fermion metals and the archetypal normal-state property of high-Tc superconductors, yet in both cases it remains…
The unusual phase has been recently observed in the organic material (TMTSF)$_{2}$PF$_{6}$, where superconductivity (SC) coexists with spin-density wave (SDW) in the pressure interval $p_{c1}<p<p_{c}$ below the first order transition into…
The superconducting (SC) state of iron-based compounds in both tetragonal and orthorhombic phases is studied on the basis of an effective Hamiltonian composed of the kinetic energy including the five Fe 3d-orbitals, the orthorhombic…
We report that intrinsic transport and magnetic properties, and their anisotropy from high quality single crystal $CaFe_2As_2$. The resistivity anisotropy ($\rho_c/\rho_{ab}$) is $\sim 50 $, and less than 150 of $BaFe_2As_2$, which arises…
Kagome metals $A$V$_3$Sb$_5$ ($A=$ K, Rb, Cs) provide a compelling platform to explore the interplay between superconductivity (SC) and charge-density-wave (CDW) orders. While distinct CDW orders have been identified in K/RbV$_3$Sb$_5$…
We present direct evidence of a superconducting state existing in the title compound below 300 mK under quasi-hydrostatic pressure. The superconducing transition is observed in the whole pressure range studied, 0 < P < 4 kbar. However, the…
The very intriguing antagonistic interplay of antiferromagnetism (AF) and superconductivity (SC), recently discovered in high-temperature superconductors, is studied in the framework of a microscopic theory. We explain the surprisingly…
This work presents and analyzes electrical resistivity data on the organic superconductor (TMTSF)$_2$ClO$_4$ and their anion substituted alloys (TMTSF)$_2$(ClO$_4$)$_{1-x}$(ReO$_4$)$_x$ along the least conducting $c^\star$ axis. Nonmagnetic…
In this article we review essential natures of superconductivity in strongly correlated electron systems (SCES) from a universal point of view. After summarizing experimental results on typical materials such as high-$T_{\rm c}$ cuprates,…
We use a variational approach to gain insight into the strongly correlated d-wave superconducting state of the high Tc cuprates at T=0. We show that strong correlations lead to qualitatively different trends in pairing and phase coherence:…
The interplay between superconductivity (SC) and spin/charge density wave (DW) in organic metals shows many similarities to high-$T_c$ superconductors. It also contains many puzzles, for example, the anisotropic SC onset observed and the…
Recently we have found that a three-dimensional superconducting state with anisotropic vortices localized at the vortex-lattice points is a stable state in zero external magnetic field for the layered high temperature uperconductivity…
One of the first finding concerning the superconducting (SC) density $n_{\rm sc}$ in cuprates was their small magnitudes that revealed the importance of phase fluctuations. More recently, measurements in a variety of overdoped cuprates…
The electron paramagnetic resonance study for an organic superconductor $\beta''$-(BEDT-TTF)$_{4}$[(H$_3$O)Ga(C$_2$O$_4$)$_3$]$\cdot$C$_6$H$_5$NO$_2$ reveals that superconductivity coexists uniformly with the charge ordered state in one…
In d$_{x^2-y^2}$-wave superconductors, the effect of s-wave point disorder has been extensively studied in the literature. In this work, we study the anisotropic disorder with a the form of $V_{kk'}^{\rm imp}=V_if_kf_{k'}$ with…
We analyze the empirical correlation between the zero temperature penetration depth $\lambda_{c}(0) $ and the corresponding normal state DC conductivity $\sigma_{c}^{DC}$, measured slightly above the transition temperature $T_{c}$, in…