Harnessing quantum tunneling: spatial transport and interferometry of ultracold atoms in optical tweezers
Optical tweezers can trap and manipulate single atoms, offering significant potential for advancing quantum technologies in computation, simulation, and sensing. Recently, we developed a tweezer array apparatus using fermionic atoms, harnessing coherent tunneling for quantum logic and wave-packet control. In this talk, I will present an experiment demonstrating Spatial Adiabatic Passage (SAP) of atoms across three tweezers via precise control of tunneling dynamics. SAP enables the transfer of a wave packet between non-directly coupled localized modes through an intermediate, unoccupied mode. I will explain how similar adiabatic processes can be extended to realize topological pumps and atomic beam splitters—key components of a novel proposal for guided atomic interferometry using optical tweezers. This interferometer allows for extended probing times, sub-micrometer positioning accuracy, and greater flexibility in shaping atomic trajectories. I will discuss two applications ideally suited to this system: measuring gravitational forces and investigating Casimir-Polder forces between atoms and surfaces. Finally, I will show how tweezer-based interferometry can be extended to clock interferometry, potentially testing the quantum twin paradox and probing quantum coherence in the context of gravitational time dilation.