Cold-atom elevator
Our recent study on reservoir-assisted preparation of topological states in published!
state is formed. (c) Cooling protocol
for state preparation, which makes use of retrieving excitations (hot atoms) from the system.
The preparation of low-entropy topological states is often hindered by heating during adiabatic preparation, since the energy gaps vanish with increasing system size. One appealing alternative is offered by bath or reservoir-engineering techniques. In this work we study, how precisely conrolled reservoirs may be used to prepare states ranging from topological edge states to small fractional quantum Hall systems. The technique is based on the spatial and temporal control of optical box traps, as used in many of our quantum-gas experiments. This enables the engineering of system-reservoir configurations, in view of preparing and manipulating topological atomic states in optical lattices. First, we consider the injection of particles from the reservoir to the system: this scenario is shown to be particularly well suited to activating energy-selective chiral edge currents, but also to prepare fractional Chern insulating ground states. Then, we devise a practical evaporative-cooling scheme to effectively cool down atomic gases into topological ground states. Our open-system approach to optical-lattice settings provides a new path for the investigation of ultracold quantum matter, including strongly correlated and topological phases.
Original publication:
Cold-Atom Elevator: From Edge-State Injection to the Preparation of Fractional Chern Insulators
Botao Wang, Monika Aidelsburger, Jean Dalibard, André Eckardt, and Nathan Goldman
Phys. Rev. Lett. 132, 163402
