相关论文: Quasiparticle evolution and pseudogap formation in…
Superconductivity emerges from the cuprate antiferromagnetic Mott state with hole doping. The resulting electronic structure is not understood, although changes in the state of oxygen atoms appear paramount. Hole doping first destroys the…
A theory of a pseudogap phase of high-temperature superconductors where current carriers are translation invariant bipolarons is developed. A temperature T* of a transition from a pseudogap phase to a normal one is calculated. For the…
We utilize steady-state and transient optical spectroscopies to examine the responses of nonthermal quasiparticles with respect to orbital modifications in normal-state iron-chalcogenide superconductors. The dynamics shows the emergence of…
We present femtosecond time-resolved pump-probe spectroscopic studies of a pseudogap (PG) along with the superconducting (SC) gap in an overdoped iron pnictide Ca(Fe0.927Co0.073)2As2. It is seen that the temperature evolution of the…
The cuprate superconductors display several characteristic temperatures which decrease as the material composition is doped, tracing lines across the temperature-doping phase diagram. Foremost among these is the pseudogap transition. At a…
Electronic nematicity is the spontaneous loss of rotational symmetry in a metal, without breaking translational symmetry. In the cuprate superconductors, there is experimental evidence for nematicity, but its origin remains unclear. Here we…
We have studied the Nernst coefficient, v(T), of epitaxial thin films of the superconductor Y1-xCaxBa2Cu3Oy with x =0.05 and x = 0.1. The x = 0.1 sample has been measured at three different values of y, in the over- (OV), optimally- (OP),…
Through the measurements of magnetic field dependence of specific heat in $La_{2-x}Sr_xCuO_4$ in zero temperature limit, we determined the nodal slope $v_\Delta$ of the quasiparticle gap. It is found that $v_\Delta$ has a very similar…
We report the out-of-plane resistivity in the systematically oxygen-controlled single crystals Bi$_{1.74}$Pb$_{0.38}$Sr$_{1.88}$CuO$_{6+\delta}$ in magnetic fields parallel to the c-axis. Two characteristic temperatures $T^*$ and $T^{**}$…
We investiaged the optical properties of four-layer BaRuO$_{3}$, which shows a fermi-liquid-like behavior at low temperature. Its optical conductivity spectra clearly displayed the formation of a pseudogap and the development of a coherent…
Optical-pump terahertz-probe spectroscopy is used to investigate ultrafast far-infrared conductivity dynamics during the insulator-to-metal transition (IMT) in vanadium sesquioxide (V2O3). The resultant conductivity increase occurs on a…
Overshadowing the superconducting dome in hole-doped cuprates, the pseudogap state is still one of the mysteries that no consensus can be achieved. It has been suggested that the rotational symmetry is broken in this state and may result in…
Superconductivity is a quantum phenomenon caused by bound pairs of electrons. In diverse families of strongly correlated electron systems, the electron pairs are not bound together by phonon exchange but instead by some other kind of…
A superconducting state is characterized by the gap in the electronic density of states which vanishes at the superconducting transition temperature Tc. It was discovered that in high temperature superconductors a noticeable depression in…
We provide a new perspective on the pseudogap physics for attractive fermions as described by the three-dimensional Hubbard model. The pseudogap in the single-particle spectral function, which occurs for temperatures above the critical…
Optical conductivity measurements on a BaCoS2 single crystal show an unusual linear behavior over a broad spectral range. In the paramagnetic phase above 300 K, the spectrum shows no gap, which contradicts the previously proposed scenario…
The existence of a pseudogap above the critical temperature has been widely used to explain the anomalous behaviour of the normal state of high-temperature superconductors. In two dimensions the existence of a pseudogap phase has already…
We present new measurements of the thermal conductivity of UPt3 down to very low temperatures (16mK) and under magnetic fields (up to 4 T) which cover all the superconducting phases of UPt3. The measurements in zero field are compared with…
Combining electronic Raman scattering experiments with cellular dynamical mean field theory, we present evidence of the pseudogap in the superconducting state of various hole-doped cuprates. In Bi2Sr2CaCu2O8+d we track the superconducting…
Polarized electronic Raman scattering from the NCCO superconductor at optimal electron doping (T_c=22 K) reveals the formation of an anisotropic pseudogap below a characteristic temperature T* ~ 220 K and energy E*_g = 850 cm-1. Below T* a…