Work extraction from coherently activated maps via quantum switch

Understand

We characterize the impact that the application of two maps in a quantum-controlled order has on the process of work extraction via unitary cycles and its optimization.

• The control is based on the quantum switch model that applies maps in an order not necessarily compatible with the underlying causal structure and, in principle, can be implemented experimentally.
• First, we show that the activation of quantum maps through the quantum switch model always entails a non-negative gain in ergotropy compared to their consecutive application.
• We also establish a condition that the maps should fulfill in order to achieve a non-zero ergotropic gain.