Arizona State University team models qubit behavior with Volterra equations

Jimmie Adriazola of Arizona State University and Katarzyna Roszak of the FZU, Institute of Physics of the Czech Academy of Sciences have developed a new framework for modeling qubit dynamics by representing the reduced density matrix as a four-dimensional state vector. This approach casts the dynamics as a Volterra equation, enabling the team to learn equations of motion for open quantum systems. Their work demonstrates that using Padé approximants to model correlation functions captures complex temporal behaviors, including oscillatory memory and algebraic tails, even for systems like the non-rotating-wave quantum Rabi model where traditional analytical solutions fail.…