Quantum Otto engine driven by quantum fields

Abstract

We consider a quantum Otto engine using an Unruh-DeWitt particle detector model which interacts with a quantum scalar field in curved spacetime. We express a generic condition for extracting positive work in terms of the effective temperature of the detector. This condition reduces to the well-known positive work condition in the literature under the circumstances where the detector reaches thermal equilibrium with the field. We then evaluate the amount of work extracted by the detector in two scenarios: an inertial detector in a thermal bath and a circulating detector in the Minkowski vacuum, which is inspired by the Unruh quantum Otto engine.

Relativistic quantum Otto engine: instant work extraction from a quantum field

“…In this context, ref. [25] provides a pertinent example. The study extends the Unruh QOE to a more general relativistic QOE, where the background geometry, the state of the field (reservoir), the detector's trajectory, and the time dependence of the interaction are not specified.…”

“…A perturbative analysis of QOE utilizing a UDW detector was investigated in [25] (see [17,18,[21][22][23][24] for analyses involving a linearly accelerating UDW detector). In these scenarios, a pointlike (i.e., zero-size) UDW detector interacts with a quasi-free state over a finite time duration.…”

“…See also [21][22][23][24] for subsequent studies. The Unruh QOE concept extends to scenarios where a UDW detector follows an arbitrary timelike trajectory in curved spacetime [25]. We will refer to quantum heat engines that include relativistic effects as 'relativistic quantum heat engines.…”