Exact ground and excited states of a t-J ladder doped with two holes

Abstract

A two chain ladder model is considered described by the strong coupling $t-t^{\prime }-J-J^{\prime }$ Hamiltonian. For the case of two holes moving in a background of antiferromagnetically interacting spins, exact, analytical results are derived for the ground state energy and low-lying excitation spectrum. The ground state is a bound state of two holes with total spin S=0. The charge excitation is gapless and the spin excitation has a gap. The corresponding wavefunctions are also exactly determined. The bound hole pair is found to have symmetry of the d-wave type. In the limit of strong rung coupling, the model maps onto an effective hard core boson model which exhibits dominant superconducting pairing correlations.

LaTeX, 15 pages, 5 PS figures, accepted in Journal of Physics: Condensed Matter

References in corpus (4)

• One-Dimensional Fermi liquids
• Weak Coupling Phase Diagram of the Two Chain Hubbard Model
• Properties of lightly doped t-J two-leg ladders
• The ground state of the two-leg Hubbard ladder: a density--matrix renormalization group study

Cited by in corpus (5)

• Experiments on Ladders Reveal a Complex Interplay between a Spin-Gapped Normal State and Superconductivity
• Phase diagram of an exactly solvable t-J ladder model
• Single hole doped strongly correlated ladder with a static impurity
• Formation of clusters in the ground state of the $t-J$ model on a two leg ladder
• Spin-interactions in Mineral Libethenite Series: Evolution of Low-dimensional Magnetism