Ground State Properties of the Doped 3-Leg t-J Ladder

TL;DR

This study investigates the ground state properties of a doped 3-leg t-J ladder using DMRG, revealing doping-dependent behaviors including a dilute hole gas, spin gap emergence, and d-wave-like pairing tendencies.

Contribution

It provides detailed numerical analysis of doping effects on spin and charge correlations in a 3-leg t-J ladder, highlighting new phenomena such as domain walls and pairing symmetry.

Findings

Holes form a dilute gas at low doping

Spin correlations decay as a power law, indicating no spin gap initially

At higher doping, a spin gap appears and pairing correlations with d-wave symmetry are observed

Abstract

Results for a doped 3-leg t-J ladder obtained using the density matrix renormalization group are reported. At low hole doping, the holes form a dilute gas with a uniform density. The momentum occupation of the odd band shows a sharp decrease at a large value of k_F similar to the behavior of a lightly doped t-J chain, while the even modes appear gapped. The spin-spin correlations decay as a power law consistent with the absence of a spin gap, but the pair field correlations are negligible. At larger doping we find evidence for a spin gap and as x increases further we find 3-hole diagonal domain walls. In this regime there are pair field correlations and the internal pair orbital has d_x^2-y^2 - like symmetry. However, the pair field correlations appear to fall exponentially at large distances.