Abstract
Significant aspects of advanced quantum technology today rely on rapid control of atomic matterwaves with hyperfine Raman transitions. Unfortunately, efficient Raman excitations are usually accompanied by uncompensated dynamic phases and coherent spin leakages, preventing accurate and repetitive transfer of recoil momentum to large samples. We provide a systematic study to demonstrate that the limitations can be substantially overcome by dynamically programming an adiabatic pulse sequence. Experimentally, counterpropagating frequency-chirped pulses are programmed on an optical delay line to parallelly drive five hyperfine Raman transitions of atoms for spin-dependent kick (SDK) within ns, with an inferred fidelity. Aided by numerical modeling, we demonstrate that by alternating the chirps of successive pulses in a balanced fashion, accumulation of nonadiabatic errors including the spin leakages can be managed, while the dynamic phases can be robustly cancelled. Operating on a phase-stable delay line, the method supports precise, fast, and flexible control of spinor matterwave with efficient Raman excitations.
- Received 19 February 2022
- Revised 5 May 2022
- Accepted 9 September 2022
DOI:https://doi.org/10.1103/PRXQuantum.3.040301
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
Published by the American Physical Society
Physics Subject Headings (PhySH)
Popular Summary
Atoms are ideal quantum sensors. To register spatial-dependent interactions, atoms are split into a superposition of displaced paths to accumulate the phase difference. This atom interferometric insight is widely exploited in state-of-the-art technologies from atom-based quantum measurements and simulations to ion-based quantum computation. A cornerstone in these developments is to split matterwave by exerting path-dependent stimulated optical forces, a technique known for its typically moderate fidelity. We show that by directly encoding hyperfine alkaline “spins” to the interferometric paths, spin-dependent recoil kicks (SDK) can be robustly driven by Raman pulses with exquisite precision.
Our technique is a high-speed extension of traditional Raman matterwave control, operated in a previously unfavored regime prone to unwanted multilevel dynamics. We find the seemingly complex internal-state dynamics can be managed with composite pulses for precise control of the multiple spins defined on the hyperfine manifold. The speed is key to freezing the continuous atomic motion and to protecting cancellation of low-frequency noises. Experimentally, the counterpropagating short pulses are spatially resolved on an optical delay line to facilitate directional “kicks” with wideband optical pulse programming. We impart hundreds of photon recoils within a few microseconds to a mesoscopic sample. Our numerical model suggests that the SDK technique can robustly support multirecoil transfer to multispinor matterwave with level phase-gate fidelity.
The fast and precise SDK is important for quantum-enhanced precision measurements with spin-squeezed samples. With improved laser power, our SDK technique may also drastically enhance the large-momentum-splitting benefits for inertial sensing with atom interferometers.
