Related papers: Direct evidence for Cooper pairing without a spect…
In most superconductors the transition to the superconducting state is driven by the binding of electrons into Cooper-pairs. The condensation of these pairs into a single, phase coherent, quantum state takes place concomitantly with their…
The discovery of the pseudogap in the cuprates created significant excitement amongst physicists as it was believed to be a signature of pairing, in some cases well above the room temperature. In this "pre-formed pairs" scenario, the…
For high-Tc superconductors, clarifying the role and origin of the pseudogap is essential for understanding the pairing mechanism. Among the various models describing the pseudogap, the preformed Cooper pair model is a potential candidate.…
Electron pairing along with phase coherence generates superconductivity below the critical temperature ($T_c$). In underdoped high-$T_c$ cuprates, these two quantum phenomena may occur at separate temperatures, which was lately confirmed in…
In the quest to understand high-temperature superconductivity in copper oxides, a vigorous debate has been focused on the pseudogap - a partial gap that opens over portions of the Fermi surface in the 'normal' state above the bulk critical…
The mutual interaction between Cooper pairs is proposed as a mechanism for the superconducting state. Above $T_c$, pre-existing but fluctuating Cooper pairs give rise to the unconventional {\it pseudogap} (PG) state, well-characterized by…
In classical superconductors Cooper-pair formation and phase coherence occur simultaneously as the temperature is lowered below Tc. In high-temperature superconductors (HTSC), on the other hand, the small superfluid density and low…
In superconductors, electrons bound into Cooper pairs conduct a dissipationless current. The strength of the Cooper pairs scales with the value of the critical transition temperature (Tc). In cuprate high-Tc superconductors, however, the…
The normal state of strongly coupled superconductors is characterized by the presence of "preformed" Cooper pairs well above the superconducting critical temperature. In this regime, the electrons are paired, but they lack the phase…
Pairing of electrons in conventional superconductors occurs at the superconducting transition temperature Tc, creating an energy gap D in the electronic density of states (DOS). In the high-Tc superconductors, a partial gap in the DOS…
The most profound effect of disorder on electronic systems is the localization of the electrons transforming an otherwise metallic system into an insulator. If the metal is also a superconductor then, at low temperatures, disorder can…
It is generally believed that in a superconducor Cooper pairs are broken at above-critical current region, corresponding to the lost of superconductivity. We suggest that, under some circumstance, Cooper pairs could still exist above…
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…
We derive a phase diagram for the pseudogap onset temperature $T^*$ (associated with the breakdown of the Fermi liquid state, due to strong pairing correlations) and the superconducting instability, $T_c$, as a function of variable pairing…
The temperature evolution of the proximity effect in Au/La$_{2-x}$Sr$_x$CuO$_4$ and La$_{1.55}$Sr$_{0.45}$CuO$_4$/La$_{2-x}$Sr$_x$CuO$_4$ bilayers was investigated using scanning tunneling microscopy. Proximity induced gaps, centered at the…
In many unconventional superconductors, the presence of a pseudogap - a suppression in the electronic density of states extending above the critical temperature - has been a long-standing mystery. Here, we employ combined \textit{in situ}…
It is proposed that in high temperature superconductors Cooper pairs form and condense due to the monotonic-oscillatory transition in the pair potential of mean force, which occurs quite generally at high coupling in charge systems. It is…
We address the origin of the Cooper pairs in high-$T_c$ cuprates and the unique nature of the superconducting (SC) condensate. Itinerant holes in an antiferromagnetic background form pairs spontaneously, without any `glue', defining a new…
The key ingredients in any superconductor are the Cooper pairs, in which two electrons combine to form a composite boson. In all conventional superconductors the pairing strength alone sets the majority of the physical properties including…
The interplay between unconventional Cooper pairing and quantum states associated with atomic scale defects is a frontier of research with many open questions. So far, only a few of the high-temperature superconductors allow this intricate…