相关论文: Fermi surface dichotomy of the superconducting gap…
The condensation of paired fermions into superfluid states changes progressively depending on the coupling strength. At the midpoint of the crossover between Bardeen--Cooper--Schrieffer (BCS) weak-coupling and Bose--Einstein condensate…
High-temperature superconductivity in iron pnictides occurs when electrons are doped into their antiferromagnetic (AF) parent compounds. In addition to inducing superconductivity, electron-doping also changes the static commensurate AF…
PdTe has recently been reported to be a type-II Dirac semimetal while a bulk nodal and surface nodeless superconductivity (SC) has been claimed to coexist. In this work, we applied point-contact spectroscopy (PCS) method to systematically…
The lack of nesting of the electron and hole Fermi-surface sheets in the Fe-based superconductor LiFeAs, with a critical temperature of 18 K, has led to questions as to whether the origin of superconductivity in this material might be…
From temperature and magnetic field dependent point-contact spectroscopy on the ferromagnetic superconductor Sr$_{0.5}$Ce$_{0.5}$FBiS$_2$ (bulk superconducting $T_c$ = 2.5 K) we observe (a) a pseudogap in the normal state that sustains to a…
Superconducting metal dichalcogenides (MDCs) present several similarities to the other layered superconductors like cuprates. The superconductivity in atomically thin MDCs has been demonstrated by recent experiments, however, the…
The pseudogap state is one of the peculiarities of the cuprate high temperature superconductors. Here we investigate its presence in BaCo$_{x}$Fe$_{2-x}$As$_{2}$, a member of the pnictide family, with temperature dependent scanning…
Upon application of an external tuning parameter, a magnetic state can be driven to a normal metal state at zero temperature. This phenomenon is known as quantum criticality and leads to fascinating responses in thermodynamics and transport…
A theory of strongly correlated electron or hole liquids with the fermion condensate is presented and applied to the consideration of quasiparticle excitations in high temperature superconductors, in their superconducting and normal states.…
The recent observation of quantum oscillations in underdoped high-Tc superconductors, combined with their negative Hall coefficient at low temperature, reveals that the Fermi surface of hole-doped cuprates includes a small electron pocket.…
The physics of the pseudogap state is intimately linked with the pairing mechanism that gives rise to superfluidity in quantum gases and to superconductivity in high-Tc cuprates, and therefore, both in quantum gases and superconductors, the…
Central issues in the electronic structure of underdoped cuprate superconductors are to clarify the shape of the Fermi surfaces and the origin of the pseudogap. On the basis of the model proposed by Kamimura and Suwa, which bears important…
This article reviews the current status of precursor superconducting phase fluctuations as a possible mechanism for pseudogap formation in high-temperature superconductors. In particular we compare this approach which relies on the…
In a recent paper Saini et al. have reported evidence for a pseudogap around (pi,0) at room temperature in the optimally doped superconductor Bi2212. This result is in contradiction with previous ARPES measurements. Furthermore they…
Understanding doped Mott insulators is a fundamental goal in condensed matter physics, with relevance to cuprate superconductors and other quantum materials. The doped Hubbard model minimally describes such systems, and has explicated some…
Cuprate high-T_c superconductors on the Mott-insulating side of "optimal doping" (with respect to the highest T_c's) exhibit enigmatic behavior in the non-superconducting state. Near optimal doping the transport and spectroscopic properties…
We review the contribution of infrared spectroscopy to the study of the pseudogap in high temperature superconductors. The pseudogap appears as a depression of the frequency dependent conductivity in the c-axis direction and seems to be…
We reanalyze the data on the in-plane far infrared conductivity of underdoped orthoII YBa$_{2}$Cu$_{3}$O$_{6.50}$ (YBCO$_{6.50}$) in terms of a model in which a pseudogap opens on part of the Fermi surface with the remaining ungaped piece…
Ultracold atomic Fermi gases can be tuned to interact strongly, where they display spectroscopic signatures above the superfluid transition reminiscent of the pseudogap in cuprates. However, the extent of the analogy can be questioned,…
High-temperature superconductivity in the cuprates emerges from an enigmatic metallic state, known as the pseudogap, characterized by a reconstructed Fermi surface, reduced carrier density, and the appearance of Fermi arcs, whose origin…