Related papers: Optical Conductivity in a Simple Model of Pseudoga…
The standard theory of metals, Fermi liquid theory, hinges on the key assumption that although the electrons interact, the low-energy excitation spectrum stands in a one-to-one correspondence with that of a non-interacting system. In the…
We analyze the anomalies of superconducting state within a simple exactly solvable model of the pseudogap state, induced by fluctuations of ``dielectric'' short range order, for the model of the Fermi surface with ``hot'' patches. The…
The real part of the optical in-plane conductivity of p-- and n--type cuprates thin films at various doping levels was deduced from highly accurate reflectivity measurements. We present here a comprehensive set of optical spectral weight…
I present a simple analytical model describing the normal state of a superconductor with a pseudogap in the density of states, such as in underdoped cuprates. In nearly two-dimensional systems, where the superconducting transition…
Here I extend my last work about the origin of the pseudo-gaps in underdoped cuprates (arXiv: cond-mat. 1011.3206), to include the mechanism of superconductivity. This is done by adapting the formalism of the double correlations in systems…
Spectral functions are evaluated numerically within the t-t'-J model as relevant for electron-doped cuprates. The Fermi surface develops from a pocket-like into a large one with doping. The corresponding pseudogap in the nodal direction is…
Ultracold atomic Fermi gases present an opportunity to study strongly interacting Fermi systems in a controlled and uncomplicated setting. The ability to tune attractive interactions has led to the discovery of superfluidity in these…
In a recent experiment [M. Feld et al., Nature 480, 75 (2011); B. Froehlich et al., Phys. Rev. Lett. 109,130403 (2012)], a pairing gap was detected in a two-dimensional (2D) Fermi gas with attractive interaction at temperatures where…
We investigate the c-axis optical conductivity and d.c. resistivity of cuprate superconductors in the normal state. Assuming that the interlayer hopping is incoherent we express the conductivity with planar spectral functions obtained (i)…
We present a theory of optical conductivity in systems with finite-momentum Cooper pairs. In contrast to the BCS pairing where AC conductivity is purely imaginary in the clean limit, there is nonzero AC absorption across the superconducting…
We investigate strong-coupling properties of a two-dimensional ultracold Fermi gas in the normal phase. In the three-dimensional case, it has been shown that the so-called pseudogap phenomena can be well described by a (non-self-consistent)…
We analyze the interaction-induced renormalization of single-particle excitations in the two-dimensional Hubbard model at weak coupling using the Wick-ordered version of the functional renormalization group. The self energy is computed for…
We apply strong magnetic fields of H=28.5 \sim 43 T to suppress superconductivity (SC) in the cuprates Bi_{2}Sr_{2-x}La_xCuO_{6+\delta} (x=0.65, 0.40, 0.25, 0.15 and 0), and investigate the low temperature (T) normal state by ^{63}Cu…
We investigate theoretically the many-body pairing of a strongly correlated two-dimensional Fermi gas with and without negative confinement-induced effective range. Using a strong-coupling effective field theory in the normal state, we show…
We study the spectral function of the pseudogap phase of quasi one-dimensional charge density wave materials. Using a stochastic approach and emphasizing an exact treatment of non-Gaussian order parameter fluctuations we will go beyond a…
Studies of the electronic spectral function in cuprates by Angle-Resolved Photo-Emission Spectroscopy reveal unusual features in the pseudogap phase that persist in the superconducting phase. We address here these observations based on the…
Cluster dynamical mean field methods are used to calculate the normal and anomalous components of the electron self energy of the two dimensional Hubbard model. From these the evolution of the superconducting gap and the momentum dependent…
Reconstruction of the Fermi surface of high-temperature superconducting cuprates in the pseudogap state is analyzed within nearly exactly solvable model of the pseudogap state, induced by short-range order fluctuations of antiferromagnetic…
Fermi liquid theory is remarkably successful in describing the transport and optical properties of metals; at frequencies higher than the scattering rate, the optical conductivity adopts the well-known power law behavior $\sigma_1(\omega)…
We discuss the optical conductivity of several non-interacting two-dimensional (2D) semiconducting systems focusing on gapped Dirac and Schr\"odinger fermions as well as on a system mixing these two types. Close to the band-gap, we can…