The stability of hole bound states in the $t\ensuremath{-}J$ model including short-range Coulomb interactions is analyzed using computational techniques on ladders with up to $2\ifmmode\times\else\texttimes\fi{}30$ sites. For a nearest-neighbor (NN) hole-hole repulsion, the two-holes bound state is surprisingly robust and breaks only when the repulsion is several times the exchange $J.$ At $\ensuremath{\sim}10%$ hole doping the pairs break only for a NN repulsion as large as $V\ensuremath{\sim}4J.$ Pair-pair correlations remain robust in the regime of hole binding. The results support electronic hole-pairing mechanisms on ladders based on holes moving in spin-liquid backgrounds. Implications in two dimensions are also presented. The need for better estimations of the range and strength of the Coulomb interaction in copper oxides is remarked.The stability of hole bound states in the $t\ensuremath{-}J$ model including short-range Coulomb interactions is analyzed using computational techniques on ladders with up to $2\ifmmode\times\else\texttimes\fi{}30$ sites. For a nearest-neighbor (NN) hole-hole repulsion, the two-holes bound state is surprisingly robust and breaks only when the repulsion is several times the exchange $J.$ At $\ensuremath{\sim}10%$ hole doping the pairs break only for a NN repulsion as large as $V\ensuremath{\sim}4J.$ Pair-pair correlations remain robust in the regime of hole binding. The results support electronic hole-pairing mechanisms on ladders based on holes moving in spin-liquid backgrounds. Implications in two dimensions are also presented. The need for better estimations of the range and strength of the Coulomb interaction in copper oxides is remarked.

arXiv:cond-mat/9803314Physical review. B, Condensed matterJan 1, 199918 citations

Effect of Coulomb interaction on the spectral functions of a 1D electron liquid

Yasha Gindikin, Vladimir A. Sablikov

Physics of low-Dimensional structuresJan 1, 20020 citations

Shape of Wigner Crystals and Hole Self-Doping in a Mexican-Hat Dispersion

Minho Kim, Xiao-Gang Wen

We study Wigner crystals (WCs) induced by a strong Coulomb interaction from the ring-like Fermi surface of a Mexican-hat dispersion $ε_k= c_2k^2+c_4k^4$ . We design orbital shape in order to minimize the energy of the WC, and find that a low ground-state energy requires an orbital shape with a depletion of electrons near $k=0$ . To capture the Coulomb-induced correlations, we include a Jastrow factor as well as a factor describing the correlation between electrons and doped vacancies. Using variational Monte Carlo calculations, we calibrate the effective band parameters $c_2$ and $c_4$ to reproduce the two transitions observed experimentally as the electron density is lowered: from a spin-valley-polarized Fermi liquid with a disk-like Fermi surface, to one with a ring-like Fermi surface, and finally to a WC. We find that, even with an optimized orbital shape that depletes electrons near $k=0$ , a WC with hole self-doping near $k=0$ can still be energetically favorable near the WC transition, provided that the electron-vacancy correlation is included. We also estimate the dispersion of the doped hole.We study Wigner crystals (WCs) induced by a strong Coulomb interaction from the ring-like Fermi surface of a Mexican-hat dispersion $ε_k= c_2k^2+c_4k^4$. We design orbital shape in order to minimize the energy of the WC, and find that a low ground-state energy requires an orbital shape with a depletion of electrons near $k=0$. To capture the Coulomb-induced correlations, we include a Jastrow factor as well as a factor describing the correlation between electrons and doped vacancies. Using variational Monte Carlo calculations, we calibrate the effective band parameters $c_2$ and $c_4$ to reproduce the two transitions observed experimentally as the electron density is lowered: from a spin-valley-polarized Fermi liquid with a disk-like Fermi surface, to one with a ring-like Fermi surface, and finally to a WC. We find that, even with an optimized orbital shape that depletes electrons near $k=0$, a WC with hole self-doping near $k=0$ can still be energetically favorable near the WC transition, provided that the electron-vacancy correlation is included. We also estimate the dispersion of the doped hole.

arXiv:2608.00170Jul 31, 20260 citations

Two-component Fermi liquid with electron-hole pairing

E. P. Fetisov, A. B. Khmelinin

Journal of Experimental and Theoretical PhysicsApr 1, 19780 citations

High-Tc superconductivity within t-J-V-Vʹ model

Srijani Ghosh, Krishanu Roy, Nanda Kumar Ghosh

We present numerical results on the role of next-nearest-neighbor (NNN) Coulomb repulsion within t-J-V-Vʹ model using exact diagonalization (ED) technique within an 8 – site tilted square cluster at a hole doping <h>=0.25. Periodic boundary conditions have been applied to obtain complete basis states. It appears that hole-hole correlation is dominant at d = √2. NNN Coulomb repulsion localizes the electrons and cooperates with exchange interaction J. Non-Fermi liquid behavior of the model has been confirmed.We present numerical results on the role of next-nearest-neighbor (NNN) Coulomb repulsion within t-J-V-Vʹ model using exact diagonalization (ED) technique within an 8 – site tilted square cluster at a hole doping <h>=0.25. Periodic boundary conditions have been applied to obtain complete basis states. It appears that hole-hole correlation is dominant at d = √2. NNN Coulomb repulsion localizes the electrons and cooperates with exchange interaction J. Non-Fermi liquid behavior of the model has been confirmed.

AIP conference proceedingsJan 1, 20200 citations

Breakdown of Fermi liquid in correlated electron systems

Claudio Castellani, C. Di Castro

Physica A Statistical Mechanics and its ApplicationsFeb 1, 19996 citations

J.

At $\ensuremath{\sim}10%$ hole doping the pairs break only for a NN repulsion as large as $V\ensuremath{\sim}4J.$ Pair-pair correlations remain robust in the regime of hole binding. The results support electronic hole-pairing mechanisms on ladders based on holes moving in spin-liquid backgrounds. Implications in two dimensions are also presented. The need for better estimations of the range and strength of the Coulomb interaction in copper oxides is remarked.

We study Wigner crystals (WCs) induced by a strong Coulomb interaction from the ring-like Fermi surface of a Mexican-hat dispersion

ε_k= c_2k^2+c_4k^4

. We design orbital shape in order to minimize the energy of the WC, and find that a low ground-state energy requires an orbital shape with a depletion of electrons near

k=0

. To capture the Coulomb-induced correlations, we include a Jastrow factor as well as a factor describing the correlation between electrons and doped vacancies. Using variational Monte Carlo calculations, we calibrate the effective band parameters

c_2

and

c_4

to reproduce the two transitions observed experimentally as the electron density is lowered: from a spin-valley-polarized Fermi liquid with a disk-like Fermi surface, to one with a ring-like Fermi surface, and finally to a WC. We find that, even with an optimized orbital shape that depletes electrons near

k=0

, a WC with hole self-doping near

k=0

can still be energetically favorable near the WC transition, provided that the electron-vacancy correlation is included. We also estimate the dispersion of the doped hole.