Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 2610.23210

Fractionalized Fermi Liquid and d-wave Superconductivity in Ba2CuO3+x

M. S. Laad·S. Koley·A. Taraphder
View original source ↗Read source document ↗Export metadata ↓

Abstract

Strongly enhanced superconductivity (SC) (Tc = 73 K) in Ba2CuO3+x (BCO) challenges the longheld paradigm of the irrelevance of the dz2-like states in cuprates. Using tight-binding band structure plus dynamical mean-field theory (TB+DMFT), we find that a fractionalized Fermi liquid (FFL) is the normal state for the parameters realistic for BCO. Transport properties exhibit strange metal behavior above Tcoh~38 K, supporting a direct instability of this strange metal to SC. Irrelevance of one-fermion inter-band mixing, itself a non-trivial consequence of the FFL state, preferentially enhances two-fermion hopping processes and provides a novel route for both SC and competing excitonic order(s) arising directly from the FFL. The proposed scenario also clarifies the role of dz2 band in shaping the physical responses of BCO.

Explore related subjects

cond-mat.str-el

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

M. S. Laad, S. Koley, A. Taraphder. 2026-10-16. Fractionalized Fermi Liquid and d-wave Superconductivity in Ba2CuO3+x. https://arxiv.org/abs/2610.23210

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Chiral Valence-Bond Solid and Chiral Triplons

We propose a chiral valence-bond solid (VBS) in which spin-singlet bond order itself spontaneously acquires handedness without magnetic order. Using a spin-lattice model on the diamond lattice, we demonstrate two enantiomorphic VBS states. In the presence of anisotropic spin interactions, this emergent handedness is inherited by chiral triplons with spin-split bands and spin textures that reverse between the two enantiomers. These textures generate a temperature-gradient-induced net spin response whose sign is set by the VBS handedness. The imaginary off-diagonal components of the dynamical spin structure factor encode the triplon polarization and change sign between the two enantiomers, enabling direct detection of chiral triplons and the selected handedness by polarized inelastic neutron scattering. Our results establish a direct connection between spontaneous chirality and magnetic excitations, opening avenues for exploring the interplay between quantum magnetism and chiral physics.

cond-mat.str-el↗
arXiv2026

Quantum Well Resonant Tunneling Diode Probe of Correlated States in Twisted Bilayer MoS$_2$

Moiré superlattices formed in transition metal dichalcogenides (TMDs) offer a versatile platform for exploring emergent quantum phases arising from strong electronic correlations. In this work, we develop a new experimental platform, the quantum well resonant tunneling diode (QWRTD), to probe the electronic landscape of $\approx 56.1^\circ$ twisted bilayer MoS$_2$ (tMoS$_2$). By measuring the differential conductance ($dI/dV_{\text{Probe}}$) as a function of filling factor $ν$ and displacement field $D$, we observe a robust integer insulating feature at $ν= 1$ that persists across the measured displacement field range. Furthermore, we identify a displacement-field-induced fractional insulating feature near $ν= 3/4$ for $D < -75$~mV/nm. Its temperature dependence is consistent with a generalized Wigner crystal interpretation, although the microscopic order remains to be established. These features are also observed in another device with a similar twist angle ($\approx 56.4^\circ$). Our results provide evidence of correlated states in near-AB-stacked tMoS$_2$ and establish QWRTD as a tool for investigating strong correlations in van der Waals heterostructures.

cond-mat.str-el↗
arXiv2026

Dynamical vertex approximation for retarded interactions: Application to the Hubbard-Holstein model

We extend the dynamical vertex approximation (D$Γ$A), in its most commonly used ladder-version, to systems with retarded electronic interactions. Such an extended scheme, which we name "dynamical-$U$ D$Γ$A", allows us to study strongly interacting electrons coupled to bosons including non-local spatial correlations on all length scales on top of the purely local ones captured by dynamical mean-field theory. We demonstrate the applicability of the method in the specific case of the coupling to a single dispersionless phononic mode, by studying the Hubbard-Holstein model on the square and cubic lattices, focusing on regimes of sizable Hubbard interactions where strong electronic correlations compete with phonon-mediated interactions. As illustrative examples, we consider the antiferromagnetic phase in the three-dimensional model and the d-wave superconductor in two dimensions, analyzing the effect of the electron-phonon coupling, including its frequency dependence, on both instabilities.

cond-mat.str-el↗