  The main question we address is how to probe the fractionalized excitations
of a quantum spin liquid (QSL), for example, in the Kitaev honeycomb model. By
analyzing the energy spectrum and entanglement entropy, for antiferromagnetic
couplings and a field along either [111] or [001], we find a gapless QSL phase
sandwiched between the non-Abelian Kitaev QSL and polarized phases. Increasing
the field strength towards the polarized limit destroys this intermediate QSL
phase, resulting in a considerable reduction in the number of frequency modes
and the emergence of a beating pattern in the local dynamical correlations,
possibly observable in pump-probe experiments.
