Magnetic and superconducting ground states can compete, cooperate and coexist. MnP provides a compelling and potentially generalizable example of a material where superconductivity and magnetism may be intertwined. Using a synchrotron-based non-resonant X-ray magnetic diffraction technique, we reveal a spiral spin order in MnP and trace its pressure evolution towards superconducting order via m...

From detailed angle-resolved NMR and Meissner measurements on a ferromagnetic (FM) superconductor UCoGe (T(Curie)∼2.5  K and T(SC)∼0.6  K), we show that superconductivity in UCoGe is tightly coupled with longitudinal FM spin fluctuations along the c axis. We found that magnetic fields along the c axis (H∥c) strongly suppress the FM fluctuations and that the superconductivity is observed in the ...

Unique superconductivity at surfaces/interfaces, as exemplified by LaAlO3/SrTiO3 interfaces, and the high transition temperature in ultrathin FeSe films, have triggered intense debates on how superconductivity is affected in atomic and electronic reconstructions. The surface of superconducting cubic spinel oxide LiTi2O4 is another interesting system because its inherent surface electronic and a...

We demonstrate that crystalline color superconductivity may arise as a result of pairing between massless quarks and quarks with nonzero mass ms. Previous analyses of this phase of cold dense quark matter have all utilized a chemical potential difference δμ to favor crystalline color superconductivity over ordinary BCS pairing. In any context in which crystalline color superconductivity occurs ...

An important problem in high temperature superconductivity is that of understanding, and ultimately controlling, fluxoid motion. Results are presented in this paper which were obtained using a new technique for measuring the pressure dependence of the transition to superconductivity in a diamond-anvil cell. By monitoring the third harmonic of the acsusceptibility, we observe the onset of irreve...

We study the transition temperature Tc(H) of a quasi-one-dimensional (Q1D) superconductivity which is derived from the quantum effect of an electron motion in a strong magnetic field. We calculate Tc(H) of both isotropic and anisotropic superconductivity by taking account of the optimal momentum of the Cooper pairs and the effect of higher harmonic terms along second conducting axis in the tigh...

We report bulk superconductivity at 1.0 K in a low-dimensional ternary telluride Ta3Pd3Te14 containing edge-sharing PdTe2 chains along crystallographic b axis, similar to the recently discovered superconductor Ta4Pd3Te16. The electronic heat capacity data show an obvious anomaly at the transition temperature, which indicates bulk superconductivity. The specific-heat jump is ΔC/(γ(n)T(c)) ≈ 1.35...

We report a non-magnetic impurity effect on the superconductivity observed in (TMTSF)2ClO4. By varying the sample cooling rate in the vicinity of an anion ordering transition at TAO = 24 K, we can systematically control the amount of disorder in the sample. We then use dc transport and microwave periodic orbit resonance measurements (closely related to cyclotron resonance) to determine the crit...

We have studied the superconducting and magnetic properties of Fe1+ySexTe1−x single crystals (0≤x≤0.5) by magnetic susceptibility, muon-spin rotation, and neutron diffraction. We find three regimes of behavior: (i) commensurate magnetic order for x≲0.1, (ii) bulk superconductivity for x∼0.5, and (iii) a range x≈0.25-0.45 in which superconductivity coexists with incommensurate magnetic order. Th...

We report the synthesis of BaPt2As2 single crystals and the discovery of superconductivity and a structural phase transition in this compound by measuring the electrical resistivity, magnetic susceptibility and specific heat as well as the X-ray diffraction at low temperatures. BaPt2As2 crystallizes in the CaBe2Ge2-type tetragonal structure (P4/nmm) at room temperature and undergoes a first-ord...