Strong coupling analysis of QED$_3$ for excitation spectrum broadening in undoped high-temperature superconductor

TL;DR

This paper applies strong coupling QED3 theory to analyze spectral broadening in undoped high-temperature superconductors, revealing a Gaussian quasiparticle spectrum with significant broadening due to gauge field interactions.

Contribution

It introduces a strong coupling analysis of gauge field interactions in QED3 to explain spectral broadening in undoped high-Tc superconductors, highlighting the system's strong coupling regime.

Findings

Fermionic quasiparticle spectrum is Gaussian with width ~3J

Energy shift comparable to quasiparticle bandwidth

System is in strong coupling regime with gauge field interactions

Abstract

Theory of quantum electrodynamics in three spatial-time dimension is applied to the two-dimensional $S=1/2$ quantum Heisenberg antiferromagnet in order to investigate a doped hole in high-temperature superconductors. Strong coupling analysis of the U(1) gauge field interaction is carried out to describe spectral broadening observed in the undoped compounds. It is found that the fermionic quasiparticle spectrum is of Gaussian form with the width about 3J, with J being the superexchange interaction energy. The energy shift of the spectrum is on the order of the quasiparticle band width, which suggests that the system is in the strong coupling regime with respect to the gauge field interaction describing the phase fluctuations about the staggered flux state.