04/03/2025
A team of researchers, including scientists from the Institute of Nanoscience at Cnr (Cnr Nano), has demonstrated for the first time that the internal magnetic structure of a molecule can be controlled using infrared radiation. The study, a result of an international collaboration between Cnr Nano, the University of Strasbourg, the Paul Scherrer Institute, and the Laboratoire National des Champs Magnétiques Intenses in Grenoble, paves the way for new developments in quantum technologies.
In particular, the researchers have shown that it is possible to control spin chirality—a stable and robust magnetic property that holds great promise for quantum computing, where preserving quantum information is crucial. “Not all quantum properties of a molecule are equally resistant to environmental interactions,” explains Filippo Troiani from Cnr Nano, a lead author of the study. “The orientation of a molecular spin could be used to encode qubits in quantum computers, but it quickly loses its quantum properties due to interactions with surrounding nuclear spins. This work, instead, demonstrates the possibility of controlling a more 'exotic' property in certain magnetic molecules: spin chirality, which is related to the relative orientation of the molecule’s internal magnetic moments. Compared to molecular spin, spin chirality is more robust because it is less affected by nuclear spin interactions. Moreover, as shown in this study, it can be manipulated using electric fields, which are easier to focus than magnetic fields, allowing for more precise and localized control of quantum properties.”
The researchers studied a molecule (Fe3) composed of three iron ions arranged in a triangular geometry. Using far-infrared spectroscopy—a technique never before applied to complex magnetic molecules—they induced transitions that invert chirality without altering the orientation of the molecular spin.
The ability to manipulate spin chirality using electric fields, such as those associated with infrared radiation, could have significant applications in quantum computing and quantum sensing. These fields require both the precise manipulation of individual molecules and the protection of qubits from decoherence, the loss of quantum properties due to environmental interactions.
This study represents the first experimental confirmation of theoretical concepts proposed over a decade ago by Filippo Troiani in collaboration with Daniel Loss from the University of Basel, one of the leading experts on spin-based qubits. “Contributing to the validation of these pioneering ideas alongside international experimental groups has been an incredibly rewarding experience,” concludes Troiani.
Per informazioni:
Maddalena Scandola
CNR - Istituto Nanoscienze
comunicazione@nano.cnr.it
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