Charla: Hole dynamics in frustrated antiferromagnets

L. O. MANUEL

ICTP -International Centre for Theoretical Physics, Trieste, Italia

Workshop; Miniworkshop on New States of Stable and Unstable Quantum Matter; 2006

ICTP

In the last decade, the dynamics of a hole injected in an antiferromagnet matrix has been extensively studied as a possible starting point to understand the physics of doped Mott insulators. However, the effect of magnetic frustration on the hole dynamics has been little explored in the literature. In this work, we have analyzed the single hole dynamics in different magnetically ordered backgrounds (Neel, spiral, canted, and collinear states) induced by frustrating interactions. For this purpose, we have used generalized t-J models, solved with the well-known self-consistent Born approximation and Lanczos exact diagonalization methods. As a general feature, we have found that hole propagation occurs preferently at two different energy scales due to the presence of antiferromagnetic and ferromagnetic correlations in the magnetic backgrounds. At the bottom of the hole spectral function there is a many body quasiparticle excitation (spin polaron) originated in the coherent coupling of the hole with the antiferromagnetic magnon excitations. On the other hand, the coupling with the ferromagnetic component of the order gives rise to a slightly perturbated free hole motion at higher energies. Finally, we discuss possible implications of our results for ARPES experiments on antiferromagnets.