Related papers: Comparative study of organic metals and high-T$_c$…
We review some properties of quasi-one-dimensional organic conductors, such as the Bechgaard salts, with an emphasis on aspects related to the crossovers between a Mott insulating state to a metallic state, and crossovers between different…
The in-plane resistivity and out-of-plane resistivity of non-superconducting RBCO (R = Y, Tm) and Fe-doped Bi2212 single crystals are discussed. The comparison of electrical transport properties of the cuprates and quasi-one dimensional…
Studies on the interplay between the charge order and the $d$-wave superconductivity in the copper-oxide high $T_{\rm c}$ superconductors are reviewed with a special emphasis on the exploration based on the unconventional concept of the…
We analyze superconductivity in the cuprates near the onset of an incommensurate charge density wave (CDW) order with momentum ${\bf Q} = (Q,0)/(0,Q)$, as observed in the experiments. We first consider a semi-phenomenological charge-fermion…
The experimentally measured phase diagram of cuprate superconductors in the temperature-applied magnetic field plane illuminates key issues in understanding the physics of these materials. At low temperature, the superconducting state gives…
We study the charge-density-wave order and its competition with superconductivity in the one-band Hubbard model for high-$T_c$ superconducting cuprates. We use cluster dynamical mean field theory (CDMFT) at $T=0$. The one-band Hubbard model…
We shall review our recent works on d-wave density wave (dDW) and gossamer superconductivity (i.e. d-wave superconductivity in the presence of dDW) in high-T$_{c}$ cuprates and CeCoIn$_{5}$. a) We show that both the giant Nernst effect and…
We analyze incommensurate charge-density-wave (CDW) and pair-density-wave (PDW) orders with transferred momenta $(\pm Q,0)$/$(0,\pm Q)$ in underdoped cuprates within the spin-fermion model. Both orders appear due to exchange of spin…
We present comparative analysis of superconducting and charge-density-wave orders in the spin-fluctuation scenario for the cuprates. That spin-fluctuation exchange gives rise to d-wave superconductivity is well known. Several groups…
Starting with a minimal model for the CuO$_2$ planes with the on-site Hilbert space reduced to a charge triplet of the three effective valence centers [CuO$_4$]$^{7-,6-,5-}$ (nominally Cu$^{1+,2+,3+}$) with different conventional spin,…
To address the issues of superconducting and charge properties in high-T$_c$ cuprates, we perform a quantum Monte Carlo study of an extended three-band Emery model, which explicitly includes attractive interaction $V_{OO}$ between oxygen…
Metal-insulator transition accompanied by charge-ordering has been widely investigated in quasi-one-dimensional conductors, including in particular organic charge-transfer solids. Among such materials the 1/4-filled band charge-transfer…
A phase diagram is drawn in a parameter space of the nearly half-filled single band two-dimensional Hubbard model with U/t, t'/t and n as the parameters, U, t, t' and n being the on-site interaction, the nearest and second nearest neighbor…
High-temperature cuprates superconductors are characterised by the complex interplay between superconductivity (SC) and charge density wave (CDW) in the context of intertwined competing orders. In contrast to abundant studies for hole-doped…
Since the discovery of cuprate high-Tc superconductivity, numerous theoretical frameworks have been proposed to explain its mechanism; Anderson's RVB picture [Science 235, 1196-1198, 1987] and U(1) gauge theory [Phys. Rev. Lett. 76,…
One of the most puzzling facts about cuprate high-temperature superconductors in the lightly doped regime is the coexistence of uniform superconductivity and/or antiferromagnetism with many low-energy charge-ordered states in a…
We study the Ginzburg-Landau free energy functional for two coupled U(1) charge order parameters describing two non-equivalent charge orders with wave vector ${\bf Q}$ detected in X-ray and STM measurements of underdoped cuprates. We do not…
The interplay of nearly degenerate orders in quantum materials can lead to a myriad of emergent phases. A prominent case is that of the high-Tc cuprates for which the relationship between superconductivity and a short-ranged, incommensurate…
We posit that there exist deep and fundamental relationships between the above seemingly very different materials. The carrier concentration-dependences of the electronic behavior in the conducting organic charge-transfer solids and layered…
Within the Composite Operator Method (COM), we report the solution of the Emery model (also known as p-d or three band model), which is relevant for the cuprate high-Tc superconduc- tors. We also discuss the relevance of the often-neglected…