Electric fields represent an ideal means for controlling spins at the nanoscale and, more specifically, for manipulating protected degrees of freedom in multispin systems. Here we perform low-temperature magnetic far-IR spectroscopy on a molecular spin triangle (Fe3) and provide the first experimental evidence of spin-electric transitions in polynuclear complexes. The co-presence of electric- and magnetic-dipole transitions, allows us to estimate the spin-electric coupling. Based on spin Hamiltonian simulations of the spectra, we identify the observed transitions and introduce the concept of a generalized exchange qubit. This applies to a wide class of molecular spin triangles, and includes the scalar chirality and the partial spin sum qubits as special cases.
@article{arxiv.2403.11214,
title = {Observation of spin-electric transitions in a molecular exchange qubit},
author = {Florian le Mardelé and Ivan Mohelský and Jan Wyzula and Milan Orlita and Philippe Turek and Filippo Troiani and Athanassios K. Boudalis},
journal= {arXiv preprint arXiv:2403.11214},
year = {2025}
}