We will investigate whether local manipulations of the potential in a small region can act as a source or sink effectively in isolated systems modeling cold-atoms. Nevertheless, programmable atomtronic circuits may need dynamically generated sources or sinks. It is possible to use atoms from a nearby trap as a source 18, 30 and remove atoms using photon or electron beams, which acts as a sink 5, 27, 31. However, due to charge neutrality of atoms, one needs creative ways for supplying or removing atoms. While particle reservoirs like batteries play the role of source or sink in conventional electronic systems, atomic analogues of particle source or sink for atomtronics are highly desired. There is a bright future for atomtronics, and here we will address a challenging issue on driving atoms in atomtronic circuits via local manipulations. Recently, the concept of atomtronics 13, 14, 15, 16 has drawn intense attention due to intriguing experimental and theoretical studies, including quantum point contact 17, 18, atomic SQUID 19, 20, 21, 22, 23, transistor 24, capacitor 25, and open quantum systems 26, 27, 28, 29. Those new techniques also provide opportunities for testing and verifying theories of transport properties in solid state devices and cold atom systems 5, 6, 7, 8, 9, 10, 11, 12. In contrast to conventional solid state materials, ultracold atoms provide more flexibility in their structures and are controllable over a broad range of parameters such as interactions and temperature 3, 4. Recent advances in trapping and manipulating ultracold atoms in magnetic or optical potentials have brought new tools for studying non-equilibrium phenomena of many-body systems via quantum simulations 1, 2. 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. 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. This is due to conservation of energy and particle in isolated systems such as cold atoms. Although a sink potential can collect bosons in equilibrium and indicate its usefulness in the adiabatic limit, sudden switching of the potential exhibits low effectiveness in pushing bosons into it. Here we consider dynamically emerged local potentials as controllable source and sink for bosonic atoms. While batteries offer electronic source and sink for electronic devices, atomic analogues of source and sink and their theoretical descriptions have been a challenge in cold-atom systems.
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