  Unambiguous identification of the Kitaev quantum spin liquid (QSL) in
materials remains a huge challenge despite many encouraging signs from various
measurements. To facilitate the experimental detection of the Kitaev QSL, here
we propose to use remnant charge response in Mott insulators hosting QSL to
identify the key signatures of QSL. We predict an emergent orbital
magnetization in a Kitaev system in an external magnetic field. The direction
of the orbital magnetization can be flipped by rotating the external magnetic
field in the honeycomb plane. The orbital magnetization is demonstrated
explicitly through a detailed microscopic analysis of the multiorbital
Hubbard-Kanamori Hamiltonian and also supported by a phenomenological picture.
We first derive the localized electrical loop current operator in terms of the
spin degrees of freedom. Thereafter, utilizing the Majorana representation, we
estimate the loop currents in the ground state of the chiral Kitaev QSL state,
and obtain the consequent current textures, which are responsible for the
emergent orbital magnetization. Finally, we discuss the possible experimental
techniques to visualize the orbital magnetization which can be considered as
the signatures of the underlying excitations.
