Challenges and constraints of dynamically emerged source and sink in atomtronic circuits: From closed-system to open-system approaches

TL;DR

This paper explores the challenges of implementing dynamic source and sink potentials in cold-atom systems, analyzing their effectiveness and proposing open-system approaches to improve atom transfer.

Contribution

It introduces a framework for using local potentials as sources and sinks in cold atoms and investigates open-system methods to enhance atom transfer efficiency.

Findings

Sudden potential switching is less effective due to energy and particle conservation.

Deeper potentials can attract fewer bosons, showing an inverse response.

Local cooling via Lindblad operators can improve atom transfer into sinks.

Abstract

While batteries offer electronic source and sink in electronic devices, atomic analogues of source and sink and their theoretical descriptions have been a challenge in cold-atom systems. Here we consider dynamically emerged local potentials as controllable source and sink for bosonic atoms. Although a sink potential can collect bosons in equlibrium and indicate its usefulness in the adiabatic limit, sudden switching of the potential exhibits low effectiveness in pushing bosons into it. This is due to conservation of energy and particle in isolated systems such as cold atoms. By varying the potential depth and interaction strength, the systems can further exhibit averse response, where a deeper emerged potential attracts less bosonic atoms into it. To explore possibilities for improving the effectiveness, we investigate what types of system-environment coupling can help bring bosons into a dynamically emerged sink, and a Lindblad operator corresponding to local cooling is found to serve the purpose.