Performance of a Brownian information engine through potential profiling: Optimum output requisites, heating-to-refrigeration transition, and their re-entrance

Abstract

Brownian information engine (BIE) harnesses the energy from a fluctuating environment by utilizing the associated information change in the presence of a single heat bath. The engine operates in a space-dependent confining potential and requires an appropriate feedback control mechanism. BIE utilizes the overall information (surprise) gained during the feedback cycle for the energy output. The feedback step is related to a sudden change in the potential energy and hence the information that is essential for a non-zero work output. The net (available) information, therefore, can be monitored by tuning the feedback controller and the shape of the confining potential. In this paper, we explore the effect of the shape modulation of the confining potential, which may have multiple stable valleys and unstable hills, on the available information and, hence, the performance of a BIE that operates under an asymmetric feedback protocol. For monostable trapping, a concave shape in the confining potential results in a higher work output than a convex one. We also find that hills and valleys in the confining potential may lead to multiple good operating conditions. An appropriate shape modulation can create a heater–refrigerator transition and its re-entrance due to non-trivial changes in information loss during the relaxation process.