Binding of Holes in the Hubbard Model

Adriana Moreo

Sudip Chakravarty, L. Chayes, Steven Allan Kivelson

Elbio R. Dagotto, Adriana Moreo, Robert L. Sugar +1 more

We present a new numerical method for the study of binding energies of particles in fermionic systems. Working with an imaginary chemical potential we can obtain results in the canonical ensemble by simple modifications of standard numerical techniques. We applied the technique to the two-dimensional Hubbard model observing binding of holes at half-filling on lattices of 4\ifmmode\times\else\texttimes\fi{}4 sites. For U/t=4 we estimate that the binding energy is \ensuremath{\Delta}=-0.10\ifmmode\pm\else\textpm\fi{}0.02.

Luis Antonio Pérez, C. Wang

G. Fano, F. Ortolani, Alberto Parola

We present the first exact results of the ground-state energy in the two-dimensional Hubbard model on a 4\ifmmode\times\else\texttimes\fi{}4 cluster for several values of U and fillings. The behavior of the binding energy of two holes as a function of U is discussed together with some analytical results in limiting cases. The analysis of the hole-hole correlation function allows one to determine the range of values of U where binding might be seen.

J. H. Jefferson