A quantum-dot information engine extracts optimal work across two decades of speed
Kushagra Aggarwal, Mark Mitchison, Martí Perarnau-Llobet, Natalia Ares and colleagues built an information engine from a quantum dot defined in a planar germanium quantum well, a scalable semiconductor platform.
By measuring the position of single thermally fluctuating electrons and applying feedback, the device extracts work in the spirit of Szilard's one-bit engine. They designed and implemented optimised driving protocols spanning the slow- to fast-driving regimes, achieving maximum efficiency over two decades of speed and outperforming naive protocols in both power and efficiency. They also quantified an unavoidable cost: boosting a Szilard engine's power output inflates the fluctuations of that power.
The work shows information engines becoming controllable, optimisable devices rather than proofs of principle.