Multi-particle entangled states in optical lattices and matter-wave interferometry
The possibility to probe and manipulate multi-particle quantum systems at the level of individual quantum particles has fundamental implications for the advancement of quantum metrology. The Experimental Quantum Optics Group at the University of Strathclyde in Glasgow and the Team at the Max Planck Institute for Quantum Optics in Garching carry out cutting-edge experiments in which ultracold atoms are held in optical lattices for quantum simulation of quantum many-body systems and for quantum information processing. A particular feature of the experiments in Strathclyde and Garching is the possibility to address and manipulate individual atoms of an optical lattice with an ultra-high resolution optical microscope. This makes it possible to change and measure the spin state of each underlying quantum particle with single-atom resolution. Experiments at Strathclyde also involve the development of matter-wave interferometers for precision measurements.
Scientific goals within this Max Planck Partnership will be the exploitation of massively entangled states for quantum computation and quantum metrology. These entangled states can not only be used as a resource for quantum computation, but in principle also enhance the sensitivity of measurement devices towards the Heisenberg limit. We will explore the various possibilities of creating many-particle entangled states either, e.g., in spin-dependent lattices, through coherent splitting of Bose-Einstein condensates or mesoscopic Rydberg gates. The unique possibilities of detecting individual quantum particles can be used to characterise these states with unprecedented precision. In the matter-wave interferometers, work will be extended from bosonic systems to fermions, where the lack of interatomic interactions will also lead to increased precision. Atom interferometers can be configured as gravitational sensors with applications ranging from navigation and geodesy to gravitational wave detection.
During the project duration, the research group will improve techniques for coherent single-atom manipulation in optical lattices by using optimal control techniques and technical innovations to minimise decoherence effects of the atomic quantum states. The activity in Strathclyde with spin-dependent lattices complements the work of the Garching group that uses Rydberg atoms for the realisation of long range interactions, quantum gates and the creation of mesoscopic entangled states. Central for these and other activities in quantum metrology is the development of technologies for laser cooling and trapping of atoms, such as miniaturized atom traps and methods for tailoring time-dependent light fields to manipulate atoms at the microscopic scale. These technologies will be developed and refined by the Strathclyde group such that can be integrated into the experimental setups in Garching and Strathclyde.