Virtual participation: Zoom details available here
Speaker: Dr Alessandro Lunghi, Trinity College Dublin
Title: "Spin relaxation in solid-state materials: case closed...?"
Abstract: The possibility to use of spin as a fundamental building block for quantum technologies is conditional on our ability to generate coherent quantum states and coherently drive them. Despite the success of some physical platforms based on spin, the coherence of these systems is critically limited by temperature. The interaction between spin and lattice vibrations, namely the spin-phonon coupling, is the main limitation to spin coherence, and understanding this fundamental interaction plays an important role in the design of highly coherent spin qubits. Despite its importance, spin-phonon interaction is yet not understood. In this seminar, I will show the progress in building a quantitative quantum theory of spin-phonon decoherence for solid-state materials. I will explore the theoretical framework behind relaxation theories and how it can be implemented in a fully non-parametric fashion thanks to advanced electronic structure simulations. Results for several chemical systems, ranging from molecules to solid-state defects and impurities, will be presented in order to demonstrate that a universal understanding of spin-phonon relaxation has been virtually achieved. I will then discuss how this information can be integrated together with machine learning and high-throughput numerical techniques to advance the design of new materials with ideal properties for quantum technologies based on molecular spin qubits.
Bio: Alessandro holds a Ph.D. in computational inorganic chemistry, awarded in 2016 by the University of Florence. After his postgraduate studies, he joined the group of Prof. Sanvito at the School of Physics of Trinity College Dublin, where he started working on machine learning methods for the design of new molecular materials and a universal first-principles theory of spin-phonon relaxation in magnetic molecules. In 2020 he was awarded a European Research Council Starting Grant to pursue his research vision on these topics and in 2021 he was appointed as Assistant Professor in Physics at Trinity College Dublin, where he has now established the Quantum Materials Dynamics group.
Alessandro's research group develops ab initio multi-scale computational strategies for the design of spin systems of interest for quantum science, magnetic resonance, spintronics, and many other fields. They combine advanced electronic structure theory, open quantum system theory, and machine learning in order to establish a rigorous understanding of spin dynamics and to design novel materials with tailored properties.