Hole dynamics in canted antiferromagnets : Coexistence of many-body and free-like excitations

We have analyzed the dynamics of a single hole doped in a canted antiferromagnet using the $t\text{\ensuremath{-}}J$ model. Within the self-consistent Born approximation we have found that the hole propagates at two different energy scales along the antiferromagnetic and the ferromagnetic components of the canted order, respectively. While the many body quasiparticle excitation has its origin in the coherent coupling of the hole with the magnon excitations of the antiferromagnetic component, the ferromagnetic component gives rise to a free-like hole motion at higher energies. We have found a nontrivial behavior of the hole spectral function with the canting angle $\ensuremath{\theta}$. In particular, in the strong coupling regime, the quasiparticle weight strongly depends on the momenta, vanishing inside the magnetic Brillouin zone for $\ensuremath{\theta}\ensuremath{\gtrsim}60\ifmmode^\circ\else\textdegree\fi{}$.