Dr Torsten Gaebel will give a seminar entitled:

 "Size and Surface Effects on NV Centres in Nanodiamond"

this Thursday at 2pm in Room C5C 353

Prof Charles Clarke will give a seminar entitled:

"Detecting slow neutrons with atoms"

this Thursday at 3pm in Room C5C 498

Charles Clark was chief of the NIST Electron and Optical Physics Division for 20 years before being appointed a NIST Fellow in 2010.  He currently serves as co-director of the Joint Quantum Institute (JQI), a research collaboration that includes NIST and the University of Maryland and as Program Manager, Atomic and Molecular Physics at the Office of Naval Research. His research activities are in the areas of ultracold gases, quantum information and telecommunications, and atomic and molecular phenomena on surfaces, in condensed matter, and in nuclear reactions.  He also co-developed the Digital Library of Mathematical Functions (http://dlmf.nist.gov), accompanied by the Cambridge University Press publication of “The NIST Handbook of Mathematical Functions” in 2010. He is actively engaged in spreading physics research news through social media such as Facebook and Twitter.

Professor Barry Sanders PhD DIC FAPS FInstP FOSA
iCORE Chair of Quantum Information Science
Director, Institute for Quantum Information Science

TITLE: Electrons cross a dynamically-organized inter-protein water bridge for directed efficient transfer

ABSTRACT: Efficient, directed electron transfer between proteins is an important part of metabolic processes, but how does the electron cross the inter-protein abyss? To answer this question, we study electronic coupling between the reduction-oxidation proteins methylamine dehydrogenase and amicyanin from Paracoccus denitrificans. We discover that, in the wild type, the most frequently occurring molecular configurations afford superior electronic coupling due to the presence of a water molecule hydrogen-bonded between the donor and acceptor sites of the two proteins, and we attribute the persistence of this water bridge to a protective molecular breakwater comprising hydrophobic residues surrounding the acceptor site. We conclude that the protein's surface residues enable association and docking of proteins for electron transfer, and the residues also stabilize and control inter-protein solvent dynamics to build a water bridge for efficient electron transport.

2pm Senate Room, Lincoln Building

Biography:
Professor  Barry Sanders is the iCORE Chair of Quantum Information Science and Director of the Institute for Quantum Information Science at the University of Calgary. He received his Bachelor of Science degree from the University of Calgary in 1984 and then completed a Diploma of Imperial College under the supervision of Professor T. W. B. Kibble. Subsequently he completed a PhD at Imperial College under the supervision of Professor Sir Peter Knight at Imperial College. Following completion of the PhD in 1987, he was a postdoctoral research fellow under the supervision of Professor Gerard Milburn, first at the Australian National University and then at the University of Queensland, and also under the supervision of Professor Crispin Gardiner who was then at the University of Waikato. Dr. Sanders joined the Physics Department of Macquarie University in 1991 and was there for 12 years, including 6.5 years as Department Head, before moving to Calgary in 2003.

Ass/Prof Yoko Miyamoto
The University of Electro-Communications
1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan

Title: Non-classical correlations in orbital angular momentum of photons and atoms

Abstract:
In this talk I will present our method to detect photons in orbital
angular momentum (OAM) superposition states without excess components,
and its application to the detection of non-classical correlation in
OAM between a pair of photons.  The method combines multiple diffraction
orders of an unshifted hologram with a path interferometer setup.
If one can assume that the photon pairs are correlated in OAM in the
classical sense, using this path interferometer method on just one
photon removes contributions of excess components from the coincidence
count rate curve.

I will also present our work on measuring qutrit-qutrit entanglement
of OAM states between an atomic ensemble and a photon.  A cloud of
atoms scatters a photon from the write beam into a Stokes photon to
transition to a collectively excited state.  During this process,
the difference in OAM between the write beam photon and Stokes photon
is transferred to the atom cloud.  This transferred OAM can be read
out by illuminating with a read beam and observing the generated
anti-Stokes photon.  We have analyzed correlation between the Stokes
and anti-Stokes photons in the OAM subspace m=0, ±1, and confirmed
3-dimensional entanglement.

Title: Thermal states of anyonic systems

Abstract: 

Dr Soyan Iblisdir, University of Barcelona, Spain

Title: Polarized photon qubits in curved space-time.

Authors: Aharon Brodutch and Daniel Terno
-----------------------
Abstract:
The polarization degree of freedom is frequently used to encode qubits.  Polarization  rotation is operationally meaningful only with respect to  local measurement bases.  Gravitational field may cause photon polarization  to rotate.  These rotations which are sometimes called the gravimagnetic effect usually depend on the trajectories.  For a stationary spacetime we construct local, path independent, physically motivated reference frames which can be used to set up the measurement apparatus.  Using these frames one can isolate the gravimagnetic effects (such as those caused by Kerr's black hole spin) by gauging out the geodetic terms (those that are caused by the mass). From a different perspective, the net polarization rotation results from a combination of Machian and geometric terms that lead to a gauge-independent phase for closed trajectories. We find polarization rotation to be more significant than is usually believed, indicating that it may serve as the basis for future gravity probes.

Professor Howard Carmichael,
University of Auckland

Title: "Elastic light scattering from multi-level atoms: Ground-state quantum beats and the evolution of coherence through quantum jumps"

Abstract: Quantum beats have been explored since the early days of quantum mechanics as an elementary example of quantum interference and the evolution of quantum coherence. The earliest experiments demonstrate beats in spontaneous emission, where coherence is prepared and evolves in an atomic excited state. Such coherence lives no longer than the spontaneous emission lifetime. Ground state coherences can live many orders of magnitude longer; for this reason they play a central role in quantum information science. In this talk I present results and theoretical modeling of a cavity QED experiment that realizes a novel quantum beat in the ground state of rubidium atoms [1]. Coherence is both created and read-out through spontaneous emission; thus, a beat that is normally hidden by the quantum fluctuations (incoherent spontaneous emission) is recovered as a feature of the photon correlations. In the first part of the talk I present the experiment setup, some experimental results, and a quantum trajectory simulation in excellent agreement with the measurements. I then go on to describe the evolution of the observed coherence in the presence of background spontaneous emissions, i.e., quantum jumps that map the atomic coherence from one manifold of magnetic sublevels to another. These jumps are shown to have an unexpected effect: whereas they might be expected to cause decoherence, in this experiment they produce a frequency shift, a shift that reverses the sign of the usual light shift (AC Stark effect). The frequency shift does not arise from a shifting of energy levels, i.e., from a standard perturbation, but from a phase diffusion with nonzero mean. In the last part of the talk I show that the diffusion process is a limiting case of a more general quantum stochastic dynamic that, in a different limit, causes the "Decoherence due to Elastic Rayleigh Scattering" reported recently by Uys et al. [2]. The notion of quantum measurement by the environment is used to illuminate the mechanism underlying the master equation derived by these authors.

[1] D.G. Norris, L.A. Orozco, P. Barberis-Blostein, and H.J. Carmichael, Phys. Rev. Lett. 105,
103602 (2009).

[2] H. Uys, M.J. Biercuk, A.P. VanDevender, C. Ospelkaus, D. Meiser, R. Oseri, and J.J.
Bollinger, Phys. Rev. Lett. 105, 200401 (2010).

2pm C5C 372

Biography:
Professor Carmichael is an international expert in theoretical quantum optics and has authored a seminal textbook on quantum optics. Howard Carmichael earned his PhD from the University of Waikato in New Zealand in 1977. He joined the faculty of the University of Arkansas in 1983 and moved to the University of Oregon in 1989, where he was Professor of Physics from 1991 to 2001. He is currently a member of the physics faculty at the University of Auckland where he holds the Dan Walls Chair in Theoretical Physics. He is a Fellow of the Optical Society of America, a Fellow of the American Physical Society, and a Fellow of the Royal Society of New Zealand. For his research in quantum optics he was awarded the Max Born Medal of the Optical Society of America in 2003.

Dr Matt Shaw from the Applied Physics & Materials Science Department in Caltech, will give a seminar entitled

“Toward the preparation and detection of squeezed states in a mechanical oscillator”

Abstract
Recent advances in nanofabrication technology and measurement techniques are now allowing experimenters around the world to access the quantum regime in mechanical systems, with profound implications for fundamental science, quantum information technology, and precision measurement and control. In this seminar, I will describe our recent efforts toward the preparation and detection of squeezed states in a strongly coupled electromechanical system, where the fluctuations in one quadrature of mechanical motion can be suppressed below the standard quantum limit through quantum non-demolition measurements and feedback. To realize this experiment, we have recently fabricated superconducting NbTiN membrane resonators coupled to on-chip microwave cavities without any amorphous dielectrics or lossy superconductors. Such devices can also be used to implement a wide variety of new experiments in cavity electromechanics.

Location: QSciTech Seminar Room
1st Floor C5C (West Entrance), Friday Aug 12 2pm

Dr Pieter Kok, from the University of Sheffield, will give a seminar entitled

The Ultimate Limit To Quantum Measurement

at 2pm in the QSciTech seminar room in C5C.

Dr Kok is a QSciTech visitor for a month (Aug) and will be giving this seminar and 3-4 MasterClassis on Optical Quantum Information Processing.

MasterClass 1: Tues Aug 9, 2pm
MasterClass 2: Wed Aug 10, 2pm

Dr Kok is internationally known for his contributions to optical quantum information processing and he has written a textbook on

"Introduction to Optical Quantum Information Processing"

His interests also span:

Measurement-based quantum computing
Linear optical quantum computing 
Quantum parameter estimation theory 
Quantum lithography & quantum state preparation 
Relativistic quantum information theory

Professor Myungshik Kim will give a seminar entitled

Quantum-state engineering for continuous-variable systems

in the QISS seminar room at 2pm on Monday July 11th.

He will review the state of the art as regards how one can engineer the quantum state of harmonic oscillator type systems. This has applications for photonic quantum technology, nanomechanics and superconducting quantum electrodynamics. As light background reading ...