Related papers: Universality of the Mott-Ioffe-Regel limit in meta…
We have investigated the charge dynamics and the nature of many-body interactions in La- and Pr- doped CaFe2As2. From the infrared part of the optical conductivity, we discover that the scattering rate of mobile carriers above 200 K…
High-temperature superconductivity in the copper-oxide ceramics remains an unsolved problem because we do not know what the propagating degrees of freedom are in the normal state. As a result, we do not know what are the weakly interacting…
The controversy regarding the precise nature of the high-temperature phase of 1T-TiSe2 lasts for decades. It has intensified in recent times when new evidence for the excitonic origin of the low-temperature charge-density wave state started…
The optical conductivity of a metal near a quantum critical point (QCP) is expected to depend on frequency not only via the scattering time but also via the effective mass, which acquires a singular frequency dependence near a QCP. We check…
The bad metallic phase with resistivity above the Mott-Ioffe-Regel limit, which appears also in cuprate superconductors, was recently understood by cold atom and computer simulations of the Hubbard model via charge susceptibility and charge…
Charge transport in the diffusive normal metal (DN) / insulator / $s$- and $% d $-wave superconductor junctions is studied in the presence of magnetic impurities in DN in the framework of the quasiclassical Usadel equations with the…
Electron-electron scattering usually dominates the transport in strongly correlated materials. It typically leads to pronounced resistivity maxima in the incoherent regime around the coherence temperature $T^{*}$, reflecting the tendency of…
We use a random gap model to describe a metal-insulator transition in three-dimensional semiconductors due to doping and find a conventional phase transition, where the effective scattering rate is the order parameter. Spontaneous symmetry…
High temperature copper-oxide-based superconductivity is obtained by adding carriers to insulating "parent compounds". It is widely believed the parent compounds are "Mott" insulators, in which the lack of conduction arises from anomalously…
We use low energy optical spectroscopy and first principles LDA+DMFT calculations to test the hypothesis that the anomalous transport properties of strongly correlated metals originate in the strong temperature dependence of their…
The frequency-dependent conductivity is studied for both the one-dimensional Hubbard model and a model of spinless fermions, using a selection rule, the Bethe ansatz energy eigenstates, and conformal invariance. For densities where the…
Understanding the origin of electron incoherence is the first step toward a theoretical description of the non-Fermi liquid behavior of the high-T$_{c}$ cuprate superconductors. Such electron incoherence manifests itself most evidently in…
Numerous unconventional superconductors such as cuprates, heavy-fermions, and twisted-bilayer graphene exhibit incoherent metallic transport above the superconducting critical temperature. This phenomenon cannot be described with…
Bad metals have a large resistivity without being strongly disordered. In many bad metals the Drude peak moves away from zero frequency as the resistivity becomes large at increasing temperatures. We catalogue the position and width of the…
Several studies have so far investigated transport properties of strongly correlated systems. Interesting features of these materials are the lack of resistivity saturation well beyond the Mott-Ioffe-Regel limit and the scaling of the…
Tunneling conductance spectra between a normal metal / d-wave superconductor junction under the presence of bulk impurities in the superconductor are studied. The quasiclassical theory has been applied to calculate the spatial variation of…
The frequency- and temperature-dependent optical conductivity of the copper oxide materials in the underdoped and optimal doped regimes are studied within the t-J model. The conductivity spectrum shows the unusual behavior at low energies…
Room-temperature metallicity of lightly doped SrTiO$_3$ is puzzling, because the combination of mobility and the effective mass would imply a mean-free-path (mfp) below the Mott Ioffe Regel (MIR) limit and a scattering time shorter than the…
Recently, Takenaka et al. reported that the resistivity rho(T) of theta-(BEDT-TTF)_2I_3 (theta-ET) exceeds the Ioffe-Regel resistivity by a factor of 50 at large temperatures T (``bad metal''). This was ascribed to strong correlation. We…
The microwave surface impedance measurements on cuprate superconductors provide the crucial information of the effect of the impurity scattering on the quasiparticle transport, however, the full understanding of the effect of the impurity…