In this talk I will present a novel way to speed-up isothermal processes by smoothly modifying the system-bath interaction. Considering heat engines based on such speed-ups, I will show that the corresponding efficiency at maximum power can interpolate between the Curzon-Ahlborn efficiency and the Carnot efficiency, and discuss specific protocols for each case. These analytical results will be tested with two numerical examples, namely the time-dependent Caldeira-Leggett and resonant-level models, with strong system-environment correlations taken fully into account. The possibility of implementing our proposed speed-ups with ultracold atomic impurities and mesoscopic electronic devices will also be discussed. Join work with: Nicola Pancotti, Matteo Scandi and Mark T.
Mitchison.