Quantum magnetoelectric effect in molecular crystal Dy$_3$
  Magnetoelectric properties of a molecular crystal formed by dysprosium triangular clusters are investigated. The effective spin-electric Hamiltonian is derived on the base of developed quantum mechanical model of the cluster spin structure. The magnetoelectric contribution to the free energy of the crystal is calculated. The analysis reveals several distinctive features of the magnetoelectric effect, which are not typical for conventional paramagnetic systems at low temperatures. The peculiarities are explained by the chirality of the dysprosium core of the molecules. 
D.I. Plokhov, A. I. Popov, and A. K. Zvezdin
cond-mat.mes-hall