Related papers: Two-Fluid Description for Iron-Based Superconducto…
Starting from a microscopic t-J like model and a SU(2) spin-charge separation ansatz, a relativistic continuum gauge lagrangian is obtained in the vicinity of a nodal point of the Fermi surface. The excitations in the pseudogap phase are…
We use the density matrix renormalization group method to study the interplay of the localized and itinerant behaviors in the one-dimensional Kondo-Heisenberg model. We find signatures of simultaneously localized and itinerant behaviors of…
We propose an exactly solvable momentum-space Kondo-BCS model to study heavy fermion superconductivity. The Kondo interaction is local in momentum space, which can be derived from an Anderson lattice with a Hatsugai-Kohmoto interaction…
The p-d model which well describes the CuO_2 planes of the high-Tc superconductors is studied by means of the Composite Operator Method (COM). The relevant quasi-particle excitations are represented by composite operators. As a result of…
Herewith, we review the available experimental data of thermoelectric transport properties of iron-based superconductors and parent compounds. We discuss possible physical mechanisms into play in determining the Seebeck effect, from whence…
We investigate models of electrons in the Sachdev-Ye-Kitaev class with random and all-to-all electron hopping, electron spin exchange, and Cooper-pair hopping. An attractive on-site interaction between electrons leads to superconductivity…
We propose a theoretical description of the phase diagram and physical properties in A2Fe4Se5-type (A=K, Tl) compounds based on a coexistent local moment and itinerant electron picture. Using neutron scattering and ARPES measurements to fix…
Underdoped cuprate superconductors are believed to be strongly correlated with electronic systems with small phase stiffness leading to a large phase fluctuation region is known as the pseudogap state. With increasing doping it is generally…
The electronic properties of correlated metals with a strong electron-phonon coupling may be understood in terms of a combination of Landau's Fermi-liquid theory and the strong-coupling theory of Migdal and Eliashberg. In these lecture…
We propose a minimal model describing magnetic behavior of Fe-based superconductors. The key ingredient of the model is a dynamical mixing of quasi-degenerate spin states of Fe2+ ion by intersite electron hoppings, resulting in an effective…
Spin-freezing is the origin of bad-metal physics and non-Fermi liquid (non-FL) properties in a broad range of correlated compounds. In a multi-orbital lattice system with Hund coupling, doping of the half-filled Mott insulator results in a…
We, basing on the quantum critical point (QCP)($p = 0.19 $), propose a phenomenological description on high-$T_c$ superconductivity in the cuprate superconductors, and suggest it divides the whole doping region into two parts: the…
The approach applicable for spatially inhomogeneous and time-dependent problems associated with the induced superconductivity in low dimensional electronic systems is developed. This approach is based on the Fano--Anderson model which…
Superconductivity and superfluidity of fermionic and bosonic systems are remarkable many-body quantum phenomena. In liquid helium and dilute gases, Bose and Fermi superfluidity has been observed separately, but producing a mixture in which…
We present a theoretical study of the superfluidity and the corresponding collective modes in two-component atomic Fermi gases with s-wave attraction and synthetic Rashba spin-orbit coupling. The general effective action for the collective…
We present theoretical calculations of collective modes of the one-band attractive Hubbard model which is widely used to study the s-wave superfluid phases of atomic Fermi gases of two-hyperfine states loaded in a deep optical lattice. To…
Berg, Metlitski and Sachdev, Science 338, 1606 (2012), have shown that the exchange of hidden spin fluctuations by conduction electrons with two orbitals can result in high-temperature superconductivity in copper-oxide materials. We…
The recent discovery of superconductivity coexisting with weak itinerant ferromagnetism in the $d$-electron intermetallic compound ZrZn$_{2}$ strongly suggests spin-fluctuation mediated superconductivity. {\it Ab initio} electronic…
Superconductivity in lanthanide- and actinide-based heavy-fermion metals can have different microscopic origins. Among others, Cooper pair formation based on fluctuations of the valence, of the quadrupole moment or of the spin of the…
We present a controlled perturbative approach to the low temperature phase diagram of highly inhomogeneous Hubbard models in the limit of small coupling, $t'$, between clusters. We apply this to the dimerized and checkerboard models. The…