Spinor matterwave control with nanosecond spin-dependent kicks

TL;DR

This paper demonstrates a method for rapid, precise control of atomic spinor matterwaves using dynamically programmed adiabatic pulse sequences, overcoming previous limitations of dynamic phases and spin-leakages.

Contribution

The authors introduce a novel adiabatic pulse sequence technique with chirped pulses that achieves high-fidelity spin-dependent kicks within 40 nanoseconds, improving control over atomic matterwaves.

Findings

Achieved 97.6% fidelity in spin-dependent kicks within 40 ns.

Managed non-adiabatic errors and canceled dynamic phases through alternating chirp sequences.

Demonstrated robust, fast, and flexible control of spinor matterwaves.

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 systematic study to demonstrate that the limitations can be substantially overcame by dynamically programming an adiabatic pulse sequence. Experimentally, counter-propagating frequency-chirped pulses are programmed on an optical delay line to parallelly drive five $\Delta m=0$ hyperfine Raman transitions of $^{85}$Rb atoms for spin-dependent kick (SDK) within $\tau=40$~nanoseconds, with an $f_{\rm SDK}\approx 97.6\%$ inferred fidelity. Aided by numerical modeling, we demonstrate that by alternating the chirps of successive pulses in a balanced fashion, accumulation of non-adiabatic 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.