Enhancing frequency metrology with Rydberg arrays

Jacob Hines, S. Rajagopal, Gabriel L. Moreau +4 more

We report on the creation of an array of spin-squeezed ensembles of cesium atoms via Rydberg dressing, a technique that offers optical control over local interactions between neutral atoms. We optimize the coherence of the interactions by a stroboscopic dressing sequence that suppresses super-Poissonian loss. We thereby prepare squeezed states of N=200 atoms with a metrological squeezing parameter ξ^{2}=0.77(9) quantifying the reduction in phase variance below the standard quantum limit. We realize metrological gain across three spatially separated ensembles in parallel, with the strength of squeezing controlled by the local intensity of the dressing light. Our method can be applied to enhance the precision of tests of fundamental physics based on arrays of atomic clocks and to enable quantum-enhanced imaging of electromagnetic fields.

James P. Shaffer

Jingya Wang, Zhongxiao Xu, Donghao Li

An atomic ensemble with many-body entanglement is desirable for precision measurement. As a type of such quantum state, the spin squeezed state has been pursued in both cold and warm atoms for applications of a quantum-enhanced atomic clock, interferometer, and magnetometer. Here, we report the numerical simulation of many-body dynamics in a Rydberg atomic array with dipole–dipole interaction, and evaluate the generation of spin squeezing. The method builds on the dissipative discrete truncated Wigner approximation, which combines the mean-field dynamics of a spin ensemble with Monte Carlo sampling. By taking into account experimental imperfections such as spin decoherence, we apply this approach to the dynamics in both strontium and rubidium Rydberg atomic arrays with the current available scale. This offers the possibility to accurately simulate the many-body dynamics of interacting quantum systems in achievable platforms for application of quantum simulation and quantum metrology.

Eva-Katharina Dietsche, Adrien Facon, Dorian Grosso +6 more

Amy K. Robinson, Matthew T. Simons, Joshua Gordon +1 more

Nelson Darkwah Oppong

Arrays of alkaline-earth atoms offer optical-clock qubits with long coherence times, scalability to large qubit numbers, and tunable Rydberg-mediated interactions. These features provide an ideal setting for exploring how microscopic control and entanglement can improve the performance of optical atomic clocks beyond conventional limits. This talk will cover two efforts in this area: recent results from JILA demonstrating entanglement-enhanced optical-clock operation, and a brief introduction to a new effort at Caltech towards next-generation quantum metrology with neutral-atom arrays.