2003/06/30 by A. E. Trumper, C. J. Gazza, L. O. Manuel · 1 citation
Physics and Astronomy · #Ionosphere and magnetosphere dynamics #Magnetic confinement fusion research #Physics of Superconductivity and Magnetism #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.69.184407
published as Phys. Rev. B 69, 184407 (2004) · 6 pages, 7 figures. Published version
openalex publication_date 2004/05/14 · arxiv created 2004/06/29 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate the single hole dynamics in the triangular t\ensuremath-J model. We study the structure of the hole spectral function, assuming the existence of a 120\ifmmode^∘\else\textdegree\fi magnetic N'eel order. Within the self-consistent Born approximation (SCBA) there is a strong momentum and t sign dependence of the spectra, related to the underlying magnetic structure and the particle-hole asymmetry of the model. For positive t, and in the strong coupling regime, we find that the low-energy quasiparticle excitations vanish outside the neighborhood of the magnetic Goldstone modes; while for negative t the quasiparticle excitations are always well defined. In the latter, we also find resonances of magnetic origin whose energies scale as (J/t)2/3 and can be identified with string excitations. We argue that this complex structure of the spectra is due to the subtle interplay between magnon-assisted and free-hopping mechanisms. Our predictions are supported by an excellent agreement between the SCBA and the exact results on finite-size clusters. We conclude that the conventional quasiparticle picture can be broken by the effect of geometrical magnetic frustration.