Extreme sub-wavelength arrays with Yb atoms in optical lattices

• Applicant: Professorin Dr. Monika Aidelsburger
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 561188949

One of the biggest challenges of the scientific community is bringing the fundamental concepts of quantum mechanics to realizable applications. Among the basic resources required for that are manybody entangled states of many qubits, where in quantum optics the focus is on entangling localized (e.g., atoms) and flying qubits (photons). In state-of-the-art systems, the number of entangled qubits (and therefore the scalability) of a system is limited by the interaction strength between qubits, decoherence mechanisms and its potential for integration with other devices. In addition, most quantum optical platforms for atom-photon interaction operate at visible or nearinfrared wavelengths (≈ 700−1000 nm), whereas for long-range communication applications telecom wavelengths (≈ 1.25 − 1.65 μm) with low loss in optical fibers are required. To address this issue, novel platforms that offer enhanced atom-atom and atom-photon interactions along with efficient frequency conversion are essential. As of today, a system that offers both long coherence times and interactions with telecom photons is yet to be found. Recently collective excitations of many emitters have attracted renewed interest due to the high-degree of control available in neutral atom arrays, which enable studies of enhanced atom-photon interactions in ordered sub-wavelength arrays. First pioneering experiments have been reported with Rb atoms in 2D arrays in a moderate subwavelength regime. Within this collaborative research grant we propose to push this to extreme regimes, where the spacing between neighboring emitters is on the order of 0.25 times the photon wavelength where significantly higher fidelities of the collective response are expected. Moreover, we propose to make use of the unique level structure of 171Yb atoms to develop a novel platform that enables a direct implementation of a subradiant response in the telecome wavelength range. In a joint collaboration between LMU and HUJI we will study potential imperfections and enhance the performance in magic-wavelength as well as extreme sub-wavelength arrays. In parallel, we will develop novel entanglement protocols that rely on recently-developed quantum information processing techniques employing the nuclear spin-1/2 degree of freedom of 171Yb and develop experimental techniques for future interfacing of the atom array metasurface with telecom photons that can be integrated into fiber-based optics. We are convinced that this will be a unique novel quantum optics platform to explore collcetive atomphoton interactions with exciting propects for future entanglement generation protocols.

• DFG Programme: Research Grants
• International Connection: Israel
• Partner Organisation: The Israel Science Foundation
• Cooperation Partner: Dr. Rivka Bekenstein