Speaker: Professor Barry Sanders
Affiliation: University of Calgary, Canada

Abstract

In quantum mechanics, physical states are represented by rays in Hilbert space H, which is a vector space imbued by an inner product |, whose physical meaning arises as the overlap ϕ|ψ for |ψ a pure state (description of preparation) and ϕ| a projective measurement. However, current quantum theory does not formally address the consequences of a changing inner product during the interval between preparation and measurement. We establish a theoretical framework for such a changing inner product, which we show is consistent with standard quantum mechanics. Furthermore, we show that this change is described by a quantum operation, which is tomographically observable, and we elucidate how our result is strongly related to the exploding topic of PT-symmetric quantum mechanics. We explain how to realize experimentally a changing inner product for a qubit in terms of a qutrit protocol with a unitary channel.

Biography

Dr. Barry Sanders is Director of the Institute for Quantum Science and Technology at the University of Calgary, Lead Investigator of the Alberta Major Innovation Fund Project on Quantum Technologies, a Distinguished Chair Professor at the University of Science and Technology China and a Vajra Visiting Faculty member of the Raman Research Institute in India. He received his Bachelor of Science degree from the University of Calgary in 1984 and a Diploma of Imperial College supervised by Professor Sir Thomas W. B. Kibble in 1985. He completed a PhD in 1987 at Imperial College London supervised by Professor Sir Peter Knight. His postdoctoral research was at the Australian National University, the University of Queensland and the University of Waikato. Dr. Sanders was on the Macquarie University faculty from 1991 until moving to Calgary in 2003.

Dr. Sanders is especially well known for seminal contributions to theories of quantum-limited measurement, highly nonclassical light, practical quantum cryptography and optical implementations of quantum information tasks. His current research interests include quantum algorithms and implementations of quantum information tasks.

Dr. Sanders is a Fellow of the Institute of Physics (U.K.), the Optical Society of America, the Australian Institute of Physics, the American Physical Society and the Royal Society of Canada, and a former Senior Fellow of the Canadian Institute for Advanced Research. He is a past President of the Australian Optical Society, past Founding Co-Chair of the Canadian Association of Physicists Division of Atomic, Molecular and Optical Physics and former Leader of the Optical Society of America Quantum Optical Science and Technology Technical Group. In 2016 Sanders was awarded the Imperial College London Doctor of Science (DSc) degree.

Dr. Sanders is a former Editor-in-Chief of New Journal of Physics, a former Associate Editor of Physical Review A, a former Editor of Optics Communications and a former Editor of Mathematical Structures of Computer Science.

About Physics Seminars

The weekly Physics Seminar series focuses on a broad range of physics research within SMP, along with frequent presentations from visiting researchers. Seminars are usually scheduled for 1.00pm on Tuesdays.

The talks are typically more specialised than a colloquium but are often attended by staff and PhD students across a broad range of areas. Speakers are thus encouraged to include introductory material in the talks.

All SMP researchers and HDR students are encouraged to speak. Please email Lewis Williamson to register your interest.

The seminars are open so there is no need to register your attendance.

Venue

Physics Annexe (06)
Room: 
407 (or via Zoom: https://uqz.zoom.us/j/94116861984)