Dynamically Enhanced Two-Photon Excitation*

We present a novel quantum control technique to generate two-photon excitation using modulated pulses, enabling the dynamic elimination (DE) of the intermediate state population [1]. The proposed DE technique excels at single-photon resonance, a feat not achieved by the well-known adiabatic elimination (AE) technique, which relies on large single-photon detuning and intense pulses to eliminate the intermediate state from the dynamics. We compare DE and AE and show that DE outperforms AE in several aspects, like its robustness to single photon detuning and fidelity. The key difference is that the effective two-photon Rabi frequency is inversely proportional to the modulation frequency and not the single-photon detuning as in AE, which leads to many of the advantages of the technique. Our technique has the potential to significantly impact the field of quantum technologies, as it addresses a critical element needed across all quantum technologies: two-photon excitation. Its simplicity, universality, and wide-ranging applicability make it an attractive solution for various fields, including atom interferometry, Rydberg-states-based technologies, quantum dots, and color centers in solids. Here, we present promising results for double-quantum Ramsey interferometry and discuss possible applications in atom interferometry.

[1] Sebastian C. Carrasco, Sean Lourette, Ignacio Sola, and Vladimir S. Malinovsky. Dynamically enhanced two-photon spectroscopy. arXiv preprint arXiv:2411.05670, 2024.