Spin Chain Connectors, Entanglement by Measurements and Mesoscopic Quantum Coherence

Lead Research Organisation: University College London
Department Name: Physics and Astronomy


Recent years have seen a rapid progress in two areas connectedwith quantum mechanics. Firstly, stimulated by the ability ofquantum mechanics to permit novel computation, there is now a world wideeffort to realize a quantum computer. Identifying viable ways toconnect and network such computers is an intrinsic part of thiseffort. This research could revolutionize information technology.Secondly, some mesoscopic systems have been shown to behavequantum mechanically in series of audacious experiments. By stretching the boundary of what we generally regard as the quantum world, they beg the question as to whether any system, however macroscopic, can be made to exhibitquantum behaviour in an appropriately designed experiment. Myresearch aims to push the boundaries of both the abovedevelopments. On the connecting and networking issue, I want to investigate how chains of spins (small one dimensional quantum magnets) can connect up quantum computers efficiently and how they can serve as a source of genuine qunatum mechanical correlations. I also want to explore whether detection of light from distant places in a efficient ways can entangle distant matter systems, even high dimensional ones. On the issue of pushing the boundaries of what we regard as the quantum world, I intend to explore whether by coupling a microscopic and a mesoscopic system one can probe the quantum nature of the latter.
Description We found how to use sudden changes in magnetic systems to generate large amounts of quantum correlations between its remotest parts. These will be useful for building quantum computers. We found a low control method of making atoms held in remote traps speak to each other to enact a logic gate for computation. We found how scattering and measurments could achive logic gates between distant magnetic moments. We suggested a way of probing quantum mechanics for macroscopic systems by using a Bose-Einstein Condensate.

The research opened up several new avenues. We suggested how networked atom-light interacting systems could simulate materials in which quantum correlations are important and for which theoretical techniques are not scalable. We also opened up a way to understand impurity systems through measures of quantum correlations arising from quantum information theory.
Exploitation Route Our findings may be useful for building scalable quantum computers, especially for its networking. Our findings will aid the simulation and understanding of strongly correlated many-body systems.
Sectors Digital/Communication/Information Technologies (including Software),Electronics,Energy