Condensed Matter Physics Seminar

Dr Marco Barbieri, University of Oxford

Thursday 30 May 2013, 1500-1600
Cavendish Colloquium Room

The Art of Quantum Networking

Scientists have debated the connection between the everyday world, and the fitful micro-world of atoms and molecules ever since the early days of quantum mechanics. We experience no palpably macroscopic objects existing simultaneously in two distinct states. How do we construct such states, and what would we do with them? More recently, the field of quantum information science (QIS) has given us new reasons to revisit these questions. QIS has revealed the possibility of radically new technologies, such as communications, sensing and computing, that outperform cognate classical implementations. These quantum information systems - essentially macroscopic quantum machines robust to decoherence - are evaluated by the cost, or the resources consumed, of performing functions. On this view, macroscopic means something that is both impossible to simulate efficiently with a conventional computer, and that maintains this quantum character even in a hostile environment. At the present time, this means a system of several tens of particles. Beyond this scale, the behaviour of the system is uncomputable, and the new physics that emerges from the construction of such systems is expected to inform research in a number of fields dealing with complex systems, such as materials science, superconductivity and molecular dynamics. In this talk, we will discuss the ongoing efforts in the Ultrafast Quantum Optics Group in Oxford to develop an optical implementation of a large scale quantum system using light - a quantum optical network - of sufficient size to access this new territory. We will review recent progress on experimental techniques, theoretical methods, and novel quantum technologies, such as quantum light sources and quantum memories.