We argue that the resonant peak observed in neutron scattering experiments on superconducting cuprates and the peak/dip/hump features observed in ARPES measurements are by-products of the same physical phenomenon. Both are due to feedback effects on the damping of spin fluctuations in a d-wave superconductor. We solve a set of coupled integral equations for fermionic and bosonic propagators, an...

We propose nanoscale magnetometry via isolated single-spin qubits as a probe of superconductivity in two-dimensional materials. characterize the magnetic field noise at qubit location, arising from current and spin fluctuations sample leading to measurable polarization decay qubit. show that due transverse studied function temperature sample-probe distance can be used extract useful information...

Spin and charge fluctuations and superconductivity in Na0.35CoO2·1.3H2O are studied based on a multi-orbital Hubbard model. By applying the fluctuation exchange (FLEX) approximation, we show that the Hund’s-rule coupling between the Co t2g orbitals causes ferromagnetic spin fluctuation. Triplet pairing is favored by this ferromagnetic fluctuation on the hole-pocket band. We propose that, in Na0...

We report Cu NMR studies on uniaxially aligned and unaligned powder samples of an electron-doped infinitely-layered high Tc cuprate superconductor Sr0.9La0.1CuO2 (Tc =42 K). We measured the nuclear spin-lattice relaxation rate 1/T1 up to 800 K. We found from the temperature dependence of 1/T1T that the wave-vector-averaged spin susceptibility is highly enhanced by spin-fluctuations in the norma...

The phenomenology of the iron pnictide superconductor can be described by three-band s± Eliashberg theory in which mechanism superconducting coupling is mediated antiferromagnetic spin fluctuations and whose characteristic energy ?0 scales with Tc according to empirical law ?0=4.65kBTc. This model presents universal characteristics that are independent critical temperature, such as link between...

We present a theory of the pinning of dynamic spin-density-wave ~SDW! fluctuations in a d-wave superconductor by local imperfections that preserve spin-rotation invariance, such as impurities or vortex cores. The pinning leads to static spatial modulations in spin-singlet observables, while the SDW correlations remain dynamic: these are the ‘‘Friedel oscillations’’ of a spin-gap antiferromagnet...

We present a theory of the pinning of dynamic spin density wave (SDW) fluctuations in a d-wave superconductor by local imperfections which preserve spin-rotation invariance, such as impurities or vortex cores. The pinning leads to static spatial modulations in spin-singlet observables, while the SDW correlations remain dynamic: these are the ‘Friedel oscillations’ of a spin-gap antiferromagnet....

We report measurements of the de Haas–van Alphen ~DHVA! effect and ac susceptibility in the layered organic superconductor k-(BEDT-TTF)2Cu(NCS)2.The amplitude of the DHVA oscillations is attenuated over a wide field range above the irreversibility line, B irr(B), below which a rigid flux lattice is formed. Thus the DHVA effect provides a unique probe of the superconducting fluctuations at high ...

Abelian gauge theories formulated on a space-time lattice can be used as a prototype for investigating the confinement mechanism. In U(1) lattice gauge theory it is possible to perform a dual transformation of the path integral. Simulating the obtained dual theory (which corresponds to a certain limit of a dual Higgs model) including external sources, we perform a very accurate analysis of flux...

Abelian gauge theories formulated on a space-time lattice can be used as a prototype for investigating the confinement mechanism. In U(1) lattice gauge theory it is possible to perform a dual transformation of the path integral. Simulating the obtained dual theory (which corresponds to a certain limit of a dual Higgs model) including external sources, we perform a very accurate analysis of flux...