$\Lambda$-Enhanced Gray Molasses Cooling of ${}^{85}$Rb Atoms in Tweezers Using the D${}_2$ Line

Abstract

We demonstrate the implementation of $\Lambda$-enhanced gray molasses cooling on the D${}_2$ line of ${}^{85}$Rb atoms in an optical tweezer array. This technique yields lower atomic temperatures of 4.0(2) $\mu$K compared to red-detuned polarization gradient cooling, and consequently extends the $T_2^{\ast }$ coherence time of the hyperfine clock qubit by a factor of 1.5. The method is alignment-free and can be readily implemented on laser beams used for magneto-optical trapping, as it only requires frequency and phase modulation control. Our experimental observations are corroborated by a numerical model based on a semi-classical force approach extended to a four-level system, including two hyperfine states of the upper manifold that are 120 MHz apart.

10 pages, 6 figures

References in corpus (18)

• Logical quantum processor based on reconfigurable atom arrays
• Demonstration of multi-qubit entanglement and algorithms on a programmable neutral atom quantum computer
• High-fidelity parallel entangling gates on a neutral atom quantum computer
• Quantum simulation and computing with Rydberg-interacting qubits
• Energy distribution and cooling of a single atom in an optical tweezer
• Analysis of dephasing mechanisms in a standing wave dipole trap
• 2000-times repeated imaging of strontium atoms in clock-magic tweezer arrays
• A tweezer array with 6100 highly coherent atomic qubits
• Continuous operation of a coherent 3,000-qubit system
• A universal neutral-atom quantum computer with individual optical addressing and non-destructive readout
• Digital laser frequency and intensity stabilization based on the STEMlab platform (originally Red Pitaya)
• Production of large ${}^{41}$K Bose-Einstein condensates using D1 gray molasses
• Motional ground-state cooling of single atoms in state-dependent optical tweezers
• Recapture Probability for anti-trapped Rydberg states in optical tweezers
• A Generalized Theory for Optical Cooling of a Trapped Atom with Spin
• Gate fidelity, dephasing, and "magic" trapping of optically trapped neutral atom
• Fano Resonance in Excitation Spectroscopy and Cooling of an Optically Trapped Single Atom
• Fidelity Relations in an Array of Neutral Atom Qubits -- Experimental Validation of Control Noise