``String excitations'' of a hole in a quantum antiferromagnet and ARPES data

ORAL

Abstract

Recently, high resolution angle-resolved photoelectron spectra (ARPES) from cuprates have been reported where an anomalous high-energy dispersion was identified. We suggest that these ARPES results reveal the internal structure of the hole quasiparticle in quantum antiferromagnets and more importantly it is evidence for the existence of ``string-excitations'' which validate early predictions based on the $t-J$ and related models. The following features of the ARPES results are all in agreement with predictions without adjusting any parameters: (a) the energy-momentum dispersion of the string-excitations, (b) the manner in which the spectral weight is transfered to higher energy string excitations, and (c) the vanishing of the quasiparticle spectral weight near the $\Gamma$ point.

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Authors

  • Efstratios Manousakis

    MARTECH \& Physics Department, FSU, Tallahassee, FL \& University of Athens, Greece, Department of Physics, Florida State University, USA, and Department of Physics, University of Athens, Greece, MARTECH, Dept. of Physics, Florida State University and University of Athens, Greece, Florida State University, MARTECH and Physics Department, FSU, Tallahassee, FL and University of Athens, Greece, Physics Department, Florida State University, USA, and Physics Department, University of Athens, Greece