1202.1861 (Da-Yong Liu et al.)

Strongly correlated electronic states and
quasi-two-dimensionalantiferromagnetism in honeycomb lattice compound
In$_{3}$Cu$_{2}$VO$_{9}$    [PDF]

Da-Yong Liu, Ying Guo, Xiao-Li Zhang, Jiang-Long Wang, Zhi Zeng, H. Q. Lin, Liang-Jian Zou

We present electronic and magnetic properties of a honeycomb compound
In$_{3}$Cu$_{2}$VO$_{9}$ in this paper. We find that undoped parent phase is a
charge transfer insulator with an energy gap of 1.6 eV. Singly occupied
3z$^{2}$-r$^{2}$ electrons of coppers, similar to the $p_{z}$ electrons of
carbons in graphene, lie from -5 to -7 eV and contributes an antiferromagnetic
moment with S=1/2. Nonmagnetic vanadium, out of the expectation, has two
electrons in V 3d orbitals. Oxygen 2p orbitals hybridizing with a small
fraction of Cu 3d orbitals dominate the density of states near E$_{F}$. We also
estimate that the planar nearest-neighbor and next-nearest-neighbor
superexchange couplings of Cu spins are J$_{1}$$\approx$17.5 meV and
J$_{2}$$\approx$0.76 meV, giving rise to a low-dimensional antiferromagnet
\cite{Sondhi10}. We suggest that hole doping on O sites may bring about
carriers and considerably enhance the screening, driving the system from an
antiferromagnetic state to a spin liquid, or a superconducting ones, very
similar to cuprates.

View original: http://arxiv.org/abs/1202.1861