  Layered honeycomb magnets are of interest as potential realizations of the
Kitaev quantum spin liquid (KQSL), a quantum state with long-range spin
entanglement and an exactly solvable Hamiltonian. Conventional magnetically
ordered states are present for all currently known candidate materials,
however, because non-Kitaev terms in the Hamiltonians obscure the Kitaev
physics. Current experimental studies of the KQSL are focused on 4d- or
5d-transition-metal-based honeycombs, in which strong spin-orbit coupling can
be expected, yielding Kitaev interaction that dominate in an applied magnetic
field. In contrast, for 3d-based layered honeycomb magnets, spin orbit coupling
is weak and thus Kitaev-physics should be substantially less accessible. Here
we report our studies on BaCo2(AsO4)2, for which we find that the magnetic
order associated with the non-Kitaev interactions can be fully suppressed by a
relatively low magnetic field, yielding a non-magnetic material and implying
the presence of strong magnetic frustration and weak non-Kitaev interactions.
