Absence of dimerization in Seff = 1/2 skew chain multiferroic Co2V2O7

Abstract

Motivated by the multiferroic effects and quantum magnetization plateaus in the skew chain antiferromagnets T2V2O7 (T = Ni, Co), we have conducted a detailed density function theoretical study on Co2V2O7. The results show that the nearest-neighbor interchain interaction (J3/kB=−35.57 K) is not much greater than the intrachain interactions (J1/kB=−19.54 K and J2/kB=27.55 K), showing the absence of interchain dimerization of the Co ions. This indicates that the “dimer+monomer” model used for Ni2V2O7 [Cao et al., Phys. Rev. B 106, 184409 (2022)] is no longer applicable to Co2V2O7. Finally, the exact diagonalization of spin Hamiltonian, including anisotropic exchanges, produces the experimentally observed 1/2 and 3/4 magnetization plateaus.