Postdoctoral researcher Leonardo Ratini

Eigenstates Engineering to Mitigate Decoherence in Molecular Nanomagnets

Molecular nanomagnets are spin quantum systems, potentially serving as the qudits for future quantum computers. In this context, the central electronic spins define our qudit, while the surrounding nuclear spins constitute a bath that interacts with the central ones, leading to decoherence and degrading the information stored in the qudits. To suppress the effect of decoherence, we have investigated the role played by the structure of the eigenstates of the qudits in the decoherence dymanics, highlighting the crucial role played by the spin texture. We first demonstrate this result analytically, then corroborate it with numerical simulations performed on giant spins and spin systems with competing antiferromagnetic (AF) interactions, confirming our hypothesis. To derive the model Hamiltonian for these systems, we employed the Schrieffer-Wolff transformation. Moreover, we implemented the cluster correlation expansion technique to calculate the decoherence induced by baths containing up to 1000 spins. Finally, we propose a realistic molecule with competing AF interaction as a promising platform for long-lived qudits.