Spin polarons in triangular antiferromagnets

The motion of a single hole in a two-dimensional triangular antiferromagnet is investigated using the t-J model. The one-hole states are described by strings of spin deviations around the hole. Using projection technique the one-hole spectral function is calculated. For large J/t we find low-lying q uasiparticlelike bands which are well separated from an incoherent backgrou nd by a gap of order J. However, for small J/t this gap vanishes and the sp ectrum becomes broad over an energy range of several t. The results are com pared with self-consistent Born approximation calculations and numerical da ta. [S0163-1829(99)07409-3].