Quasiparticle vanishing driven by geometrical frustration

Luis Manuel

Instituto de Fisica Rosario, CONICET (Argentina), Bv 27 de Febrero 210 Bis, 2000 Rosario, Argentina

We have studied the dynamics of a single hole inyected in a triangular antiferromagnet. Using an hole-magnon effective Hamiltonian we have computed the spectral function and the quasiparticle wave function within the self-consistent Born approximation. We have found remarkable differences, under sign reversal of the integral transfer t, regarding the multi-magnon processes and the own existence of the quasiparticle excitations. Such differences are due to the subtle interplay between magnon-assisted and free hopping mechanisms. We conclude that the conventional quasiparticle picture can be broken by geometrical magnetic frustration without invoking spin liquid phases.