Related papers: Superconductivity and Spin Fluctuations
In order to discuss superconductivity in orbital degenerate systems, a microscopic Hamiltonian is introduced. Based on the degenerate model, a strong-coupling theory of superconductivity is developed within the fluctuation exchange (FLEX)…
From heavy fermions to cuprates and iron pnictides, a spin resonance is a staple of nearly magnetic superconductors. Possible explanations include a two-particle bound state or loss of magnon damping in the superconductor. While both…
We present the exact solution of a one-dimensional model of a spin-gapped correlated electron system with hybridization impurities exhibiting both magnetic and mixed-valence properties. The host supports superconducting fluctuations, with a…
I examine electron-phonon mediated superconductivity in the intermediate coupling and phonon frequency regime of the quasi-2D Holstein model. I use an extended Migdal-Eliashberg theory which includes vertex corrections and spatial…
Based on an effective two-band model and using the fluctuation-exchange (FLEX) approach, we explore spin fluctuations and unconventional superconducting pairing in Fe-based layer superconductors. It is elaborated that one type of interband…
Although correlated electronic-structure calculations explain very well the normal state of Sr$_2$RuO$_4$, its superconducting symmetry is still unknown. Here we construct the spin and charge fluctuation pairing interactions based on its…
Our measurements of $^{125}$Te NMR relaxations reveal an enhancement of electronic spin fluctuations above $\mu_0H^*\sim15$ T, leading to their divergence in the vicinity of the metamagnetic transition at $\mu_0H_m\approx35$ T, below which…
The interplay of orbital and spin degrees of freedom is the fundamental characteristic in numerous condensed matter phenomena, including high temperature superconductivity, quantum spin liquids, and topological semimetals. In iron-based…
Motivated by a recent experiment in ultracold atoms [ S. Krinner et al., Proc. Natl. Acad. Sci. U.S.A 113, 8144 (2016)], we analyze transport of attractively interacting fermions through a one-dimensional wire near the superfluid…
Ferromagnet/superconductor heterostructures allow for the combination of unique physical phenomena offered by the both fields of magnetism and superconductivity. It was shown recently that spin waves can be efficiently scattered in such…
In high-temperature cuprate superconductors, the anti-ferromagnetic spin fluctuations are thought to have a very important role in naturally producing an attractive interaction between the electrons in the $d$-wave channel. The connection…
We describe the relation between spin fluctuations and superconductivity in a highly-ordered sample of YBaCu3O6.5 using both polarized and unpolarized neutron inelastic scattering. The spin susceptibility in the superconducting phase…
We study the effect of dissipation on quantum phase fluctuations in d-wave superconductors. Dissipation, arising from a nonzero low frequency optical conductivity which has been measured in experiments below $T_c$, has two effects: (1) a…
The interplay between magnetic fluctuations and superconductivity is fundamental for understanding unconventional high-temperature superconductors. In the recently discovered Ruddlesden-Popper phase nickelates-which achieve superconducting…
We present the theory for the effects of superconducting pairing fluctuations on the nuclear spin-lattice relaxation rate, 1/T_1, and the NMR Knight shift for layered superconductors in high magnetic fields. These results can be used to…
The pairing symmetry in the electron mechanism for superconductivity is explored when charge fluctuations coexist with spin fluctuations. The extended Hubbard model is adopted to obtain, with the fluctuation exchange approximation, a phase…
We consider the SU(2) gauge theory for spin fluctuations in the two-dimensional Hubbard model, where the electron field is fractionalized in terms of spinons and chargons. In this theory, spinons are described by a non-linear sigma model,…
Motivated by recent experiments on isovalent-doped 1111 iron-based superconductors LaFeAs$_{1-{x}}$P$_{x}$O$_{1-{y}}$F$_{y}$ and the theoretical study that followed, we investigate, within the five orbital model, the correlation between the…
We analyze a model for electronic structure and interactions in twisted transition metal chalcogenide WSe$_2$ for superconductivity. In this material, spin-orbit scattering locks the z-components of spins of low-energy fermions near the…
The putative spin-triplet superconductor UTe2 exhibits multiple superconducting phases under applied pressure [D. Braithwaite et al., Commun. Phys. 2, 147 (2019)]. The clarification of pairing mechanisms and symmetries of gap functions are…