Related papers: Fluctuations and pairing in Fe-based superconducto…
The role of collective modes in various experiments on the cuprates is investigated. We calculate the neutron scattering, photoemission (ARPES), and Raman scattering intensities below $T_c$ within the fluctuation-exchange (FLEX)…
Multiband systems, which possess a wide parameter space, allow to explore a variety of competing ground states. Bright examples are the Fe-based pnictides and chalcogenides, which demonstrate metallic, superconducting, and various magnetic…
Inelastic neutron scattering was employed to investigate the impact of electronic nematic order on the magnetic spectra of LaFeAsO and Ba(Fe$_{0.953}$Co$_{0.047}$)$_{2}$As$_{2}$. These materials are ideal to study the paramagnetic-nematic…
In this study, the temperature dependence of elastic constants $C_{11}$, $C_{33}$, $C_{\rm E} = (C_{11}-C_{12})/2$, $C_{66}$ and $C_{44}$ of the iron-based superconductor Ba(Fe$_{1-x}$Co$_{x}$)$_{2}$As$_{2}$ (0 $\leqq x \leqq$ 0.245) have…
The main driven force of the electronic nematic phase in iron-based superconductors is still under debate. Here, we report a comprehensive study on the nematic fluctuations in a non-superconducting iron pnictide system…
We consider the minimal two-band model for the Fe-based superconductors with a phenomenological pairing interaction which mimics short-range antiferromagnetic (AFM) fluctuations. Two superconducting (SC) gap solutions are found to exist…
By means of neutron inelastic scattering, magnetic excitations and phonons were measured for a single crystal of slightly overdoped superconductor Ca10Pt4As8(Fe1-xPtxAs)10 (x ~ 0.2) with the transition temperature Tc of ~33 K. Below Tc,…
Electronic Raman scattering measurements have been performed on hole doped copper oxide superconductors as a function of temperature and doping level. In the superconducting state coherent Bogoliubov quasiparticles develop preferentially…
The present article reviews recent experimental investigations of spin dynamics in iron-based superconductors and their parent compounds by means of inelastic neutron scattering. It mainly focuses on the most contemporary developments in…
We use inelastic light scattering to study Sr$_{1-x}$Na$_x$Fe$_2$As$_2$ ($x\approx0.34$), which exhibits a robust tetragonal magnetic phase that restores the four-fold rotation symmetry inside the orthorhombic magnetic phase. With cooling,…
We theoretically investigate magnetic properties of a trapped ultracold Fermi gas. Including pairing fluctuations within the framework of an extended $T$-matrix approximation (ETMA), as well as effects of a harmonic trap in the local…
We consider the effect of glide-plane symmetry of the Fe-pnictogen/chalcogen layer in Fe-based superconductors on pairing in spin fluctuation models. Recent theories have proposed that so-called $\eta$-pairing states with nonzero total…
We investigate interplay between magnetic fluctuations and superconductivity in the effective five-band Hubbard model for iron-oxypnictide superconductors on the basis of the fluctuation-exchange approximation. As for the normal-state…
We investigate the pairing symmetry in heavily overdoped Ba$_{1-x}$K$_{x}$Fe$_{2}$As$_{2}$ based on the spin-fluctuation mechanism. The exotic octet nodes of the superconducting gap and the unusual evolution of the gap with doping observed…
Inelastic light scattering spectra of several members of the RFe3(BO3)4 family reveal a cascade of phase transitions as a function of temperature, starting with a structural, weakly first order, phase transition followed by two magnetic…
Effects of superconducting fluctuation (SCF) on thermodynamic properties of electron systems in the so-called BCS-BEC-crossover regime are studied. As the attractive interaction between electrons becomes stronger upon approaching the…
Strong interplay of spin and charge/orbital degrees of freedom is the fundamental characteristic of the iron-based superconductors (FeSCs), which leads to the emergence of a nematic state as a rule in the vicinity of the antiferromagnetic…
Short review of the spin-fluctuation theory of superconductive pairing in iron-based pnictides and chalcogenides.
Neutron scattering can provide detailed information about the energy and momentum dependence of the magnetic dynamics of materials provided sufficiently large single crystals are available. This requirement has limited the number of rare…
We study the relation between the spin fluctuation and superconductivity in an heavily hole doped end material KFe$_2$As$_2$. We construct a five orbital model by approximately unfolding the Brillouin zone of the three dimensional ten…