Molecular nanomagnets and chiral-induced spin selectivity: two useful tools for quantum technologies

Quantum technologies have the potential to revolutionize many aspects ranging from science to security. Molecular Nanomagnets (MNMs) [1] provide a promising tool for quantum technologies. In fact, they are often characterized by a sizeable number of low-energy states that can be coherently manipulated by microwave and radiofrequency pulses, thus opening the possibility to use them as qudits. This offers the possibility of integrating multiple quantum resources into single objects and to reduce the computational costs of some applications.

I review some recent results on molecular spin qudits/qubits. Quantum Error Correction is the holy grail of quantum computing, but it is very difficult to implement, because it usually requires a large overhead in the number of physical qubits. Here I show that exploiting the many-level structure of MNMs it is possible to encode in a single molecule a qubit with embedded Quantum Error Correction [2], thus circumventing this limitation. Moreover, I present the first operating prototype of a quantum simulator based on molecular qudits [3].

Molecular spins are thus promising, but their relatively small coupling with magnetic fields may limit their use to very low temperatures and makes difficult to readout the single molecular spin. These problems could be solved by exploiting the chiral-induced spin selectivity phenomenon. I show that this exists also at the molecular level [4,5] and could be harnessed to spin-polarize and read out the state of individual molecular qubits even at relatively high temperatures [6].



[1] A Chiesa et al, Rep. Prog. Phys. 87 (2024) 034501

[2] M. Mezzadri et al, Mater. Horiz.11 (2024) 4961

[3] S. Chicco et al, J. Am. Chem. Soc. 146, (2024) 1053

[4] H. Eckvahl et al, Science 382 (2023) 197

[5] A. Chiesa et al, Nano Lett. 24 (2024) 12133

[6] A. Chiesa et al, Adv. Mater. 2300472 (2023)