Field-induced spin-liquid-like state in a magnetic honeycomb lattice

Quantum fluctuations in magnetic lattices can yield a quantum spin-liquid (QSL) state, where no long-range order appears even at zero temperature. The variety of mechanisms that can generate the spin-liquid state and the more exotic QSL state remain unclear, however. Here, we report a magnetic honeycomb system, BaCo2(P1-xVx)(2)O-8, in which the spin correlations can be tuned by the disorder, leading to different magnetic behaviors. At low x, the material has a spin-glass ground state that appears to be due to coexisting and competing correlations. We have found that an external magnetic field can introduce spin-liquid-like behavior for some members of the solid solution, testified by the magnetic and thermodynamic experiments. Our results suggest that structural geometry, chemical disorder, and external field may help enhance quantum fluctuations in magnetic honeycomb materials.