Quasiparticle Energy Dispersion and Shadow Peaks in a Doped SO(5) Symmetric Ladder

TL;DR

This paper investigates quasiparticle excitations in a doped SO(5) symmetric ladder system, revealing the origin of energy gaps and the occurrence of shadow peaks linked to antiferromagnetic correlations.

Contribution

It provides the first combined mean field and exact diagonalization analysis of quasiparticle behavior in an SO(5) symmetric ladder, highlighting the role of rung singlet states and shadow peaks.

Findings

Energy gap caused by rung singlet states

Shadow peaks can occur above the Fermi surface

Antiferromagnetic correlations involve only rungs

Abstract

Mean field and exact diagonalization studies on the quasiparticle excitation of an SO(5) symmetric two-leg ladder system are reported. It is shown that the energy gap in the quasiparticle excitation is caused by the formation of rung singlet states. We find that shadow peaks can occur above the Fermi surface with antiferromagnetic electron correlations involving only rungs in the spin ladder.