  Rydberg atoms as versatile tools for quantum applications are extremely
sensitive to electric fields. When utilizing these atoms, it becomes imperative
to comprehensively characterize and mitigate any residual electric fields
present in the environment. Particularly for single Rydberg atoms trapped in
optical tweezers in a compact quartz vacuum cell, we have identified that a
significant source of background electric fields originates from electrons
bound to the cell surface. These electrons are generated by the 297-nm light
used for single-photon Rydberg excitation. Furthermore, once the electrons are
desorbed from the surface through exposure to ultraviolet light, the incoherent
ground-Rydberg transition undergoes a transformation into coherent excitation,
since the noise of residual electric fields are effectively mitigated. Our
studies promote enhanced control and reliable performance of Rydberg atom-based
systems, thereby paving the way for advancements in quantum information
processing, the realization of high-fidelity quantum gates, and the development
of precise quantum sensors.
