Related papers: Decoupled Pairing Amplitude and Electronic Coheren…
Identifying the mechanism of superconductivity in the high-temperature cuprate superconductors is one of the major outstanding problems in physics. We report local measurements of the onset of superconducting pairing in the high-transition…
Unconventional superconductivity is commonly linked to electronic pairing mechanisms, since it is believed that the conventional electron-phonon interaction (EPI) cannot cause sign-changing superconducting gap symmetries. Here, we show that…
Exceptional points (EPs) are degeneracies in open wave systems with coalescence of at least two energy levels and their corresponding eigenstates. In higher dimensions, more complex EP physics not found in two-state systems is observed. We…
Microscopy (STM). At all dopings, the low energy density-of-states modulations are analyzed according to a simple model of quasiparticle interference and found to be consistent with Fermi-arc superconductivity. The superconducting…
In order to understand the origin of high-temperature superconductivity in copper oxides, we must understand the normal state from which it emerges. Here, we examine the evolution of the normal state electronic excitations with temperature…
The BCS-to-BEC crossover, as well as the nature of Cooper pairs, in a superconducting and Fermi superfluid medium is studied from the exact ground state wavefunction of the reduced BCS Hamiltonian. As the strength of the interaction…
We provide a comprehensive theoretical study of the radio-frequency (rf) spectra of a two-component Fermi gas with balanced populations in the normal region of the temperature-vs-coupling phase diagram. In particular, rf spectra are…
There has been strong interest recently in the so-called Cooper pair density wave, subsequent to the proposition that such a state occurs in the hole-doped cuprate superconductors. As of now there is no convincing demonstration of such a…
We propose and investigate a model for the coexistence of Superconductivity (SC) and Ferroelectricity (FE) based on the dynamical symmetries $su(2)$ for the pseudo-spin SC sector, $h(4)$ for the displaced oscillator FE sector, and $su(2)…
High-quality polycrystalline SmFeAsO0.75 was synthesized with a superconducting transition width less than 1 K, and the electronic behavior was systematically studied by transport and specific heat measurements. An obvious superconducting…
By in-situ change of polarization a small splitting of the Zhang-Rice singlet state band near the Fermi level has been resolved for optimum doped (x=0.4) Bi$_{2}$Sr$_{2-x}$La$_{x}$CuO$_{6+\delta}$ at the (pi,0)-point (R.Manzke et al. PRB…
We use high resolution angle resolved photoemission spectroscopy and density functional theory with experimentally obtained crystal structure parameters to study the electronic properties of CaKFe4As4. In contrast to related CaFe2As2…
A new, theoretical approach to macroscopic quantum coherence and superconductivity in the p-type (hole doped) cuprates is proposed. The theory includes mechanisms to account for e-pair coupling in the superconducting and pseudogap phases…
We present a systematic angle-resolved photoemission spectroscopy study of the substitution-dependence of the electronic structure of Rb$_{0.8}$Fe$_{2}$(Se$_{1-z}$S$_z$)$_2$ (z = 0, 0.5, 1), where superconductivity is continuously…
Obtaining the electronic structure of the newly discovered iron-based superconductors is the key to understanding the mechanism of their high-temperature superconductivity. We used angle-resolved photoemission spectroscopy (ARPES) to make…
We investigate a semiconductor $p$-$n$ junction in contact with superconducting leads that is operated under forward bias as a light-emitting diode. The presence of superconductivity results in a significant increase of the…
We study the momentum-integrated quasiparticle interference (QPI) in the FeSe-based superconductors. This method was recently proposed theoretically and has been applied to determine the pairing symmetry in these materials experimentally.…
Strong electron interactions in solids increase effective mass, and shrink the electronic bands [1]. One of the most unique and robust experimental facts about iron-based superconductors [2-4] is the renormalization of the conduction band…
We study theoretically the coherent nonlinear optical response of doped semiconductors with partially occupied subbands. When the Fermi energy of an occupied subband approaches the exciton level of an upper subband, the absorption spectrum…
Superconductivity usually emerges from a metallic normal state which follows the Fermi-liquid paradigm. If, in contrast, the normal state is a fractionalized non-Fermi liquid, then pairing may either eliminate fractionalization via a…