Multiferroic triangular molecular qubits

The frustrated triangular single molecule magnets with half integer spins from an important class of molecular magnets that have potential application as qubits in quantum computing. The lack of inversion symmetry allows these molecular qubits to be manipulated by an external electric field. Among several candidate triangular molecules, Fe₃O(NC₅H₅)₃(O₂CC₆H₅)₆ molecular cation is particularly exciting since to date this is the only molecule in which the spin-electric coupling effect is observed experimentally. In this work, using standard density-functional methods, we demonstrate that the spin-electric behavior of this molecule could be even more interesting as there are energetically competitive reference states associated with both high and low local spins (S=5/2 vs. S=1/2) on the Fe³⁺ ions. Each of these spin structures allow spin-electric coupling in their respective chiral ground states. The presence of nearly degenerate reference states, composed of high-spin and low-spin centers, is of potential interest for quantum sensing applications. In this talk we will also discuss the possibility of inducing spin-crossover between the low and high spin configurations by an external electric field.