The spin and charge gaps of the half-filled N-leg Kondo ladders

TL;DR

This study investigates the spin and charge gaps in N-leg Kondo ladders at half-filling using density matrix renormalization group, revealing non-zero gaps for finite legs and providing evidence of a quantum critical point in 2D, but no superconductivity near half-filling.

Contribution

It provides the first detailed analysis of spin and charge gaps in N-leg Kondo ladders and explores the quantum critical point in the 2D Kondo lattice model.

Findings

Non-zero spin and charge gaps for any finite number of legs and J>0

Evidence of a quantum critical point in the 2D Kondo lattice model

No evidence of superconductivity near half-filling in the 2D model

Abstract

In this work, we study N-leg Kondo ladders at half-filling through the density matrix renormalization group. We found non-zero spin and charge gaps for any finite number of legs and Kondo coupling $J>0$. We also show evidence of the existence of a quantum critical point in the two dimensional Kondo lattice model, in agreement with previous works. Based on the binding energy of two holes, we did not find evidence of superconductivity in the 2D Kondo lattice model close to half-filling.