Related papers: Extended paraconductivity regime in underdoped cup…
The electrical conductivity induced near the superconducting transition by thermal fluctuations was measured in different granular aluminum films. The seemingly anomalous behavior at high reduced temperatures and magnetic fields is…
We review recent work on a continuum, classical theory of thermal fluctuations in two dimensional superconductors. A functional integral over a Ginzburg-Landau free energy describes the amplitude and phase fluctuations responsible for the…
The enigmatic scaling behaviour of the normal state properties of the high Tc cuprates has been explained by assuming that a crossover from the two- dimensional Heisenberg (2D-H) to the one-dimensional spin ladder (1D-SL) regime takes place…
A phase diagram for a 2D metal with variable carrier density has been derived. It consists of a normal phase, where the order parameter is absent; a so-called ``abnormal normal'' phase where this parameter is also absent but the mean number…
Pseudogap formation is an ubiquitous phenomena in strongly-correlated superconductors, for example cuprates, heavy-fermion superconductors, and iron pnictides. As the system is cooled, an energy gap opens in the excitation spectrum before…
The pseudogap (PG) derived from the analysis of the excess conductivity $\sigma'(T)$ in superlattices and double-layer films of $YBa_2Cu_3O_{7-\delta}$-$PrBa_2Cu_3O_{7-\delta}$(YBCO-PrBCO), prepared by pulsed laser deposition, is studied…
The superconducting state of underdoped cuprates is often described in terms of a single energy-scale, associated with the maximum of the (d-wave) gap. Here, we report on electronic Raman scattering results, which show that the gap function…
We report on an exact solution of the nearly antiferromagnetic Fermi liquid spin fermion model in the limit \pi T << \omega_{sf}, which demonstrates that the broad high energy features found in ARPES measurements of the spectral density of…
Several models of the electronic spectrum in the pseudogap state of underdoped cuprates have been proposed to explain ARPES and STM measurements, which reveal only truncated Fermi pockets instead of a full metallic Fermi surface. We…
We present magnetic susceptibility and electrical transport measurements of the highly anisotropic compound LaSb$_2$ observing a very broad transition into a clean, consistent with type-I, superconducting state with distinct features of 2…
We evaluate the superconducting fluctuation corrections to thermal conductivity in the normal state which diverge as T approaches T_c. We find zero total contribution for one, two and three-dimensional superconductors for arbitrary impurity…
We present new Au/La_{2-x}Sr_{x}CuO_{4} (LSCO) point-contact conductance measures as a function of voltage and temperature in samples with 0.08 <= x <= 0.2. Andreev reflection features disappear at about the bulk Tc, giving no evidence of…
We investigate tunable superconducting transitions in (111)$\mathrm{LaAlO}_3/\mathrm{KTaO}_3$ field-effect devices. Large increases in conductivity, associated with superconducting fluctuations, are observed far above the transition…
We describe the approach of the superconducting state as a sequence of cross-over phenomena. As the temperature is decreased, uncorrelated pairing of the electrons leads to the opening of a pseudogap at T_F^*. Upon further lowering the…
One of the most intriguing aspects of cuprates is a large pseudogap coexisting with a high superconducting transition temperature. Here, we study pairing in the cuprates from electron-electron interactions by constructing the pair vertex…
We comment on transport experiments in underdoped LaSrCuO in the non-superconducting phase. The temperature dependence of the resistance strongly resembles what is expected from standard localization theory. However this theory fails, when…
We report on a study of the electromagnetic response of three different families of high-T_c superconductors that in combination allowed us to cover the whole doping range from under- to overdoped. The discussion is focused on the ab-plane…
We consider a two dimensional semiconductor with a local attraction among the carriers. We study the ground state of this system as a function of the semiconductor gap. We find a direct transition from a superconducting to an insulating…
We review the empirical scenario emerging from the measured doping dependence of the transition temperature and the anisotropy parameter $% \gamma $ $=\xi _{ab}/\xi_{c}$, defined as the ratio of the correlation lengths parallel and…
We present a general scenario for high-temperature superconducting cuprates, based on the presence of dynamical charge density waves (CDWs) and to the occurrence of a CDW quantum critical point, which occurs, e.g., at doping p~0.16 in YBCO.…