# Basser Seminar Series

# Quantum computing – information processing and storage in quantum spin systems

Speaker: **Dr. Stephen Bartlett**

Senior Lecturer in Physics, University of Sydney

Time: Friday 27 March 2009, 4:00-5:00pm*Refreshments will be available from 3:30pm*

Location: The University of Sydney, School of IT Building, Lecture Theatre (Room 123), Level 1

Add seminar to my diary

## Abstract

Quantum physics might provide us with a powerful new way of computing, but constructing such a quantum computer is a real challenge. In the first half of my talk, I'll discuss some of these challenges, as well as some recent ideas in physics that might help us get through them. Meeting these challenges is also giving us new ideas on how to understand and manipulate complexity in many-body quantum systems.

In the second half, I'll outline some of my own research into the potential use of ground states of quantum many-body systems either as "quantum memories" or for performing quantum computing. Most proposals to construct a quantum computer involve building up an exotic quantum state "qubit by qubit''. What we have shown is that certain theoretical spin systems, when cooled down to a very low temperature, will naturally function as a quantum computer when subjected to a sequence of single-spin measurements. This way, we may be able to get Nature to build our quantum computers for us - we just have to find (or synthesize) the right material, then put it in the fridge!

## Speaker's biography

Dr. Stephen Bartlett is a Senior Lecturer in the School of Physics, University of Sydney, and leads the Quantum Information Theory group. He obtained is Ph.D. in physics at the University of Toronto in 2000. The focus of his doctoral work was the application of group theoretical methods to physics, and to problems of quantization in particular. He began investigating theoretical quantum information and quantum optics at Macquarie University as a post-doc, continuing this research as a lecturer at the University of Queensland in 2003-2004. His current research interests include quantum computation in cold spin lattices using single-spin measurements, optical quantum computation, and understanding the role of reference frames in quantum theory.