Coulomb Enhanced Superconducting Pair Correlations in the Frustrated Quarter-Filled Band

Abstract

A necessary condition for superconductivity (SC) driven by electron correlations is that electron-electron (e-e) interactions enhance superconducting pair-pair correlations, relative to the noninteracting limit. We report high-precision numerical calculations of the ground state within the frustrated two-dimensional (2D) Hubbard Hamiltonian for a wide range of carrier concentration $\rho$ (0 < $\rho$ <1) per site. We find that long range superconducting pair correlations are enhanced only for $\rho$ $\simeq$ 0.5. At all other fillings e-e interactions mostly suppress pair correlations. The enhancement of pair correlations is driven by the strong tendency to local singlet bond formation and spin gap (SG) in $\rho$ = 0.5, in lattices with quantum fluctuation. We also report determinantal quantum Monte Carlo (DQMC) calculations that are in strong agreement with our ground state results. Our work provides a key ingredient to the mechanism of SC in the 2D organic charge-transfer solids (CTS), and many other unconventional superconductors with frustrated crystal lattices and $\rho$ $\simeq$ 0.5, while explaining the absence of SC in structurally related materials with substantially different $\rho$.

arXiv comment9 pages, 4 figures; Supplementary information (see ancillary files)

References in corpus (31)

• Correlated Electrons in High Temperature Superconductors
• A Common Thread: the pairing interaction for the unconventional superconductors
• Ubiquitous Interplay between Charge Ordering and High-Temperature Superconductivity in Cuprates
• Charge order driven by Fermi-arc instability in Bi2201
• A Constrained Path Monte Carlo Method for Fermion Ground States
• Quantum frustration in organic Mott insulators: from spin liquids to unconventional superconductors
• Superconductivity and the Pseudogap in the two-dimensional Hubbard model
• Incipient charge order observed by NMR in the normal state of YBa2Cu3Oy
• Charge ordering in the electron-doped superconductor Nd2-xCexCuO4
• Properties of lightly doped t-J two-leg ladders
• Pairing Correlations in the Two-Dimensional Hubbard Model
• Evidence for structural and electronic instabilities at intermediate temperatures in $\kappa$-(BEDT-TTF)${}_2$X for X=Cu[N(CN)${}_2$]Cl, Cu[N(CN)${}_2$]Br and Cu(NCS)${}_2$: Implications for the phase diagram of these quasi-2D organic superconductors
• Mechanism of High Temperature Superconductivity in a striped Hubbard Model
• Crossover between BCS Superconductor and Doped Mott Insulator of d-wave Pairing State in Two-Dimensional Hubbard Model
• The Paired Electron Crystal: order from frustration in the quarter-filled band
• Origin of high-Tc superconductivity in doped Hubbard models and their extensions: Roles of uniform charge fluctuations
• Path-Integral Renormalization Group Method for Numerical Study on Ground States of Strongly Correlated Electronic Systems
• Electrodynamic Response of the Charge Ordering Phase: Dielectric and Optical Studies of alpha-(BEDT-TTF)2I3
• Absence of superconductivity in the half-filled band Hubbard model on the anisotropic triangular lattice
• Quantum-number projection in the path-integral renormalization group method
• Spin-liquid and magnetic phases in the anisotropic triangular lattice: the case of $\kappa$-(ET)${}_2$X
• Charge ordering in theta-(BEDT-TTF)_2 X materials
• Elastic Study of Antiferromagnetic Fluctuations in the Layered Organic Superconductors kappa-(BEDT-TTF)_2X
• BEDT-TTF organic superconductors: the entangled role of phonons
• Absence of long-range superconducting correlations in the frustrated 1/2-filled band Hubbard model
• Co-operative density wave and giant spin gap in the quarter-filled zigzag ladder
• Emergence of charge degrees of freedom under high pressure in an organic dimer-Mott insulator ${\beta }^{\prime }$-(BEDT-TTF)${}_2$ICl${}_2$
• Correlated Wave-Functions and the Absence of Long Range Order in Numerical Studies of the Hubbard Model
• Mott Transition in the Hubbard Model on Checkerboard Lattice
• The chemical physics of unconventional superconductivity
• Microscopic observation of superconducting fluctuations in $\kappa$-(BEDT-TTF)${}_2$Cu[N(CN)${}_2$]Br by ${}^{13}$C NMR spectroscopy

Cited by in corpus (19)

• Doped Mott Insulators in the Triangular Lattice Hubbard Model
• Molecular Quantum Materials: Electronic Phases and Charge Dynamics in Two-Dimensional Organic Solids
• From charge- and spin-ordering to superconductivity in the organic charge-transfer solids
• A DMRG Study of Superconductivity in the Triangular Lattice Hubbard Model
• The Valence Transition Model of Pseudogap, Charge-Order and Superconductivity in Electron- and Hole-Doped Copper Oxides
• Coulomb enhancement of superconducting pair-pair correlations in a $\frac{3}{4}$-filled model for $\kappa$-(BEDT-TTF)${}_2$X
• Charge orders in organic charge-transfer salts
• Ingredients for Generalized Models of $\kappa$-Phase Organic Charge-Transfer Salts: A Review
• Strong light-field effects driven by nearly single-cycle 7-fs light field in correlated organic conductors
• Absence of Luther-Emery Superconducting Phase in the Three-Band Model for Cuprate Ladders
• Cooperative enhancement of superconducting correlations by electron-electron and electron-phonon interactions in the quarter-filled band
• Sr${}_2$RuO${}_4$, like doped cuprates and barium bismuthate, is a negative charge-transfer gap even parity superconductor with $\frac{3}{4}$-filled oxygen band
• Simultaneous Control of Bandfilling and Bandwidth in Electric Double-Layer Transistor Based on Organic Mott Insulator $\kappa$-(BEDT-TTF)${}_2$Cu[N(CN)${}_2$]Cl
• Doping asymmetry in the three-band Hamiltonian for cuprate ladders: failure of the standard model of superconductivity in cuprates
• Theory of triangular lattice quasi-one-dimensional charge-transfer solids
• Thermal algebraic-decay charge liquid driven by competing short-range Coulomb repulsion
• Valence Transition Theory of the Pressure-Induced Dimensionality Crossover in Superconducting Sr${}_{14-x}$Ca${}_x$Cu${}_{24}$O${}_{41}$
• Absence of superconductivity in the Hubbard dimer model for kappa-(BEDT-TTF)_2X
• Study of the triangular-lattice Hubbard model with constrained-path quantum Monte Carlo