Related papers: Novel Electronic State and Superconductivity in th…
The electronic structure of a new charge-density-wave/ superconductor system, 1T-CuxTiSe2, has been studied by photoemission spectroscopy. A correlated semiconductor band structure is revealed for the undoped case. With Cu doping, the…
We examine the thermodynamic properties of the hole- and electron-doped cuprates by using the t-t'-t''-J model. We find that the chemical potential shows different doping dependence between the hole and electron dopings. Recent experimental…
The underdoped cuprates have a number of interesting and unusual properties that often seem hard to reconcile with one another. In this paper we show how many of these diverse phenomena can be synthesized into a single coherent theoretical…
It is widely believed that high-temperature superconductivity in the cuprates emerges from doped Mott insulators. The physics of the parent state seems deceivingly simple: The hopping of the electrons from site to site is prohibited because…
Within the t-t'-J model, the doping dependence of charge dynamics in electron-doped cuprates is studied. The conductivity spectrum shows a pseudogap structure with a low-energy peak appearing at $\omega\sim 0$ and an rather sharp…
The single-site two-electron exchange amplitude J_sd between the Cu 4s and Cu 3d_{x^2-y^2} states is found to be the pairing mechanism of high-T_c overdoped cuprates. The noninteracting part of the Hamiltonian spans the copper Cu 4s, Cu…
The electron-doped cuprates Pr_{2-x}Ce_xCuO_4 and Nd_{2-x}Ce_xCuO_4 have been studied by electronic Raman spectroscopy across the entire region of the superconducting (SC) phase diagram. The SC pairing strength is found to be consistent…
The superconducting transition temperature $T_{c}$ of multilayers of electron-doped cuprates, composed of underdoped (or undoped) and overdoped La% $_{2-x}$Ce$_{x}$CuO$_{4}$ (LCCO) and Pr$_{2-x}$Ce$_{x}$CuO$_{4}$ (PCCO) thin films, is found…
Combining (1) the universal correlations between $T_{c}$ and $n_{s}/m^{*}$ (superconducting carrier density / effective mass) and (2) the pseudo-gap behavior in the underdoped region, we obtain a picture to describe superconductivity in…
The density-of-states at the Fermi energy, $N(E_F)$, is low in doped superconducting semiconductors and high-$T_C$ cuprates. This contrasts with the common view that superconductivity requires a large electron-boson coupling $\lambda$ and…
Layered organic superconductors of the BEDT family are model systems for the interplay of the Mott transition with superconductivity, magnetic order and frustration. Recent experimental studies on a hole-doped version of BEDT compounds…
Unlike the hole-doped cuprates, both nodal and nodeless superconductivity (SC) are observed in the electron-doped cuprates. To understand these two types of SC states, we propose a unified theory by considering the two-dimensional t-J model…
In this paper the phase diagram of high $T_{c}$ cuprates is {\it qualitatively} studied in the context of competing orders: antiferromagnetism, d-wave superconductivity and $d$-density wave. {\it Local} correlation functions are estimated…
In this paper, we try to understand the pseudogap phenomenon observed in the cuprate superconductor through a model study. Specifically, we explore the so-called low-temperature pseudogap state by turning off the superconducting off…
The underdoped cuprate superconductors are characterized by the opening of the pseudogap, while such an aspect of the pseudogap effect should be reflected in the low-energy electronic structure (LEES). Here the effect of the pseudogap on…
In this work, the high entropy oxide A2CuO4 Ruddlesden-Popper (La0.2Pr0.2Nd0.2Sm0.2Eu0.2)2CuO4 is explored by charge doping with Ce+4 and Sr+2 at concentrations known to induce superconductivity in the simple parent compounds, Nd2CuO4 and…
Semiconducting-like low-temperature in-plane resistivity indicates that there are no remnants of superconductivity above the resistive phase transition at T > Tc in underdoped cuprates. The model with the chemical potential pinned near the…
In the framework of the effective low-energy model for High-$T_c$ cuprates with account for three-centers interaction terms and spin fluctuations the properties of normal and superconducting phases of p- and n-type cuprates are…
High-temperature superconductivity has been discovered in La2-xBaxCuO4 [1], a compound that derives from the undoped La2CuO4 crystallizing in the perovskite T-structure. In this structure oxygen octahedra surround the copper ions. It is…
We report a large-scale density-matrix renormalization group study of the lightly doped Hubbard model on 4-leg cylinders at hole doping concentration $\delta=12.5\%$. By keeping a large number of states for long system sizes, we are able to…