Toroidal moment in a family of spin-frustrated heterometallic triangular nanomagnets without spin-orbit coupling: Applications in a molecular spintronics device

We theoretically investigate a family of spin-frustrated triangular molecular nanomagnets with arbitrary on-site spin, featuring one heterometallic ion, in the limit of zero spin-orbit coupling. Analytical evaluation of the Heisenberg exchange states and spectrum shows that the ground state can either be the first example of a toroidal quartet, or feature two weakly split toroidal doublets, depending on the exchange parameters. The nonequilibrium spin dynamics of these toroidal states is modelled within a three-terminal molecular spintronics device, showing that gate and bias voltages can be used to tune the nonequilibrium population of these toroidal states, thus to monitor the ensuing toroidal magnetization of the device.