Long-range interaction using strontium atoms in an optical lattice

Quantum sensors provide unprecedented precision & accuracy, and are surpassing their classical counter parts in most of the cases. For instance, optical clocks have already reached the unprecedented precision ~1*10-18, which is unthinkable using conventional mechanical oscillators. The underpinning idea behind is about trapping and cooling of atoms to ultra low temperatures. Now thrust is on to translating these proven concepts into compact, robust and energy efficient sensors with real world applications. Such a step change demands an efficient and well-controlled atom source and optimal detection techniques. In our lab, we routinely cool millions of Sr atoms to micro Kelvin temperature. Atom shot noise is one of the fundamental barriers to an ultimate achievable precision in these quantum sensors. In our experiment, we aim to use the 3P0-3D1 transition in order to create entanglement between Sr atoms at different lattice sites [1]. This entanglement is caused by a large induced dipole moment (>3.5Debye). Entangling N atoms will increase the precision of an atomic sensor by factor of sqrt N. In this project, detection techniques will play a crucial role. Therefore, we will explore the implementation of various detection schemes. In addition to measurements of the relative particle numbers in different states and 'in-situ' fluorescence measurements with spatial resolution on the order of a few micro, we will study the use of Bragg-scattering of light on the atoms in the optical lattice as a means to identify small-scale periodic structures. We will also study time-of-flight imaging techniques to identify patterns in the momentum distribution of the sample. In fact, noise correlation methods are also very useful to identify the phases in a lattice. Within the project, there will be an opportunity to gain experience and expertise on vacuum chamber, lasers, optical-interface and computer control.