Description
We develop an experimental platform for trapping and controlling the motion of sub-micron solid particles at the quantum level in ultra-high vacuum (UHV). By integrating a stable dark optical trap within the large RF potential of a Paul trap, we combine the strengths of both approaches and overcome key limitations of conventional bright optical trapping of large masses. We demonstrate trapping conditions for resonant particles made of high-density transition-metal dichalcogenides (up to 10 g/cm³) in a blue-detuned bottle-beam trap, and our theory results show more than two orders of magnitude suppression of recoil-induced decoherence compared to standard bright-trap configurations. Since recoil heating is the dominant decoherence mechanism for optically trapped particles, dark trapping provides a clear pathway toward accessing the quantum regime of their motion. Building on this, I will also present a protocol for generating unconditional entanglement between two levitated masses interacting through a 1/r^n potential [1]. The protocol combines optimal quantum control of continuously measured particles [2] with their driven non-equilibrium dynamics, enabling entanglement generation at the fundamental conditional-state limit and requiring an order of magnitude weaker interaction strength compared to existing steady-state approaches.
[1] Poddubny et al., Nonequilibrium entanglement between levitated masses under optimal control, arXiv:2408.06251
[2] Winkler et al., Steady-state entanglement of interacting masses in free space through optimal feedback control, arXiv:2408.07492
