Quantum Optics seminar: Antonio Ortu

Lanthanide atoms in solid-state quantum memories and in optical tweezers for quantum computing

Lanthanide atoms are ubiquitous in modern day technology, and in particular they offer peculiar properties for quantum applications. In this talk, I will present my work on two different types of implementations. First, I will introduce lanthanide atoms as dopants in solid-state crystals, where they exhibit long coherence times in their nuclear and hyperfine spin states when cooled down to a few Kelvin. I will show part of the spectroscopy work that led to the discovery of long coherence times in Yb:YSO [1], and then move on to the implementation of quantum storage protocols on Eu:YSO [2].

In the second part of the talk, I will present how single lanthanide atoms can also be trapped in optical tweezers [3]. I will focus on the case of erbium, which offers a wide range of optical transitions with different, complementary properties, that can be used for the fundamental building blocks of quantum computing in neutral atoms, such as optical trapping and cooling, single-atom imaging, and excitation to Rydberg states.

[1] Ortu et al., Nat. Mat. 17 (8), 671 (2018)

[2] Ortu et al., npj Quantum Information 8, 29 (2022)

[3] Kaufman & Ni, Nat. Phys. 17, 1324–1333 (2021)

[4] Bloch et al., Phys. Rev. Lett. 131, 203401 (2023)