Dynamical Lattices, Gauge Fields, and Generalized Light Forces

The experimental development of cold gases of atoms and molecules has led to a novel set of systems which can show complex collective behaviour. In the ultracold regime (when the de Broglie wavelength exceeds the interparticle spacing) these gases must be described by quantum theory, and new forms of collective quantum behaviour can emerge.

Ultracold gases allow unprecedented control of the coherent quantum dynamics of many-particle systems. Recent experimental developments have opened up new ways in which cold gases can be controlled, by using light to imprint synthetic gauge fields. These gauge fields allow cold neutral atoms to experience effective magnetic fields, and have been shown to lead to inter-particle interactions of non-zero range and to provide ways to measure the atomic motion from spectroscopy of internal atomic states. Furthermore, the development of theories of optically induced gauge fields has identified qualitatively new forms of light-force acting on particles.

In this work we explore new opportunities that are presented by these recent advances in experimental capabilities and recent theoretical developments. We shall investigate: (1) the collective quantum behaviour of strongly interacting atoms subjected to dynamically modulated optical lattices and gauge fields: (2) Collective quantum behaviour of strongly interacting atoms coupled to a quantum gauge field; and (3) Generalized light forces on atoms and molecules.

The scientific goals of the research include: uncovering and describing new forms of collective behaviour of non-equilibrium many body systems; finding cooling strategies for atoms and molecules; and developing new ways to manipulate atoms/molecules with light. In particular, the research will explore and illuminate new possibilities for the coherent quantum control of extended many-body quantum systems.

The initial impact of the research will be in scientific advancement. The goal of the theoretical proposal is to identify new opportunities that are presented in the field of cold atom systems by very recent advances in experimental capabilities and in theory. By exploring, theoretically, the consequences of these advances in realistic settings presented by current experiments, the research will enable new methodologies in the control of cold atom systems. The scientific goals of the research include: uncovering and describing new forms of collective behaviour of non-equilibrium many body systems; finding cooling strategies for atoms and molecules; and developing new ways to manipulate atoms/molecules with light. The research will explore and illuminate new possibilities for the coherent quantum control of extended many-body quantum systems. The impact of these results on the scientific community will be immediate. A list of groups in the UK and abroad with whom direct contact is already established is included under "academic beneficiaries". The impact will be shared in the scientific community far beyond those groups where direct collaboration can be established, through the usual publication channels, seminars and conferences.

While the research is driven by exploring the new possibilities that new capabilities present, it does have potential to lead to new technological developments with economic impact. Since the research will be closely tied to ongoing experiment the new developments can be quickly realized and converted to new technologies. One area where there is potential for technological impact is in the development of methods for quantum information processing. One route to quantum information processing is provided by strongly coupled atom-light systems (an area in which there has been rapid progress recently). The theoretical exploration of many-body effects in extended systems has the potential to uncover new ways to manipulate multiple quantum degrees of freedom.

The research will lead to the training of young researchers. The work will be carried out with one PDRA, and support of 2-3 research students from separate funding. They will be trained in theoretical methods and atomic physics, facilitating careers in research environment, or in industries involving frontier technologies.