2015 Series

2015 Series

Semester 2 Talks

11/08/15 – The Path to 3D Integrated Photonics: If You Build It, He Will Come

Michael Withford

Macquarie University
The challenges encountered by 3D laser written integrated photonics are both cultural and technical in nature. In this talk we will comment on the former, review the latter and highlight new 3D enabled applications.

Mick Withford

18/08/15 – Half a Century of Research in Molecular and Optical Physics

Brian Orr

Macquarie University
August 2015 marks 50 years since I sailed off to commence my PhD studies at U ofBristol in England, so it is timely to present some personal reminiscences, strategic insights and scientific developments to which that has led. I have been lucky to work in various lively research communities, ranging from U of Sydney, thence to Bristol and NRCC Ottawa, then >45 years as an academic and researcher at UNSW and Macquarie U. My scientific narrative will show the key roles played by curiosity (motivating scientific discovery), capability (experimental and theoretical tools needed) and continuity (how one thing can lead to another). I intend to cover a wide range of research topics: how electro-optic measurements led me into the emerging fields of nonlinear optics and laser-based experiments; understanding molecular and optical processes in terms of statistical mechanics (both classical and quantum); facing the intricacies of atomic and molecular spectroscopy; time-resolved optical double-resonance investigations of spectroscopy and energy-transfer processes in small (but not so simple!) polyatomic molecules; developing optical parametric oscillators and cavity-enhanced spectroscopy (e.g., cavity ringdown) for industrial, environmental, agricultural and biomedical optical sensing; and so on…

Brian Orr

25/08/15 – Physicochemical Aspects of Laser Generated Nanostructures and some Applications

Marta Castillejo

CSIC, Madrid
In this talk I will discuss physicochemical aspects and control strategies of laser generated nanostructures, in both top down and bottom up approaches. Secondly, I will present new methodologies that we have developed for in situ determination of the processes of laser induced growth and self-assembly, including the diagnostic of complex laser ablation plasmas by nonlinear optical processes.

Marta Castillejo

01/09/15 – Quantum Physics and Precision Measurement with Ultracold Atoms

Kenneth Baldwin

Australian National University
The ability to confine and control atoms with great precision has enabled the creation of atomic ensembles at extremely low temperatures. The de Broglie waves of these atoms can overlap to form a Bose-Einstein condensate whose matter-wave properties can be used to probe fundamental quantum mechanical phenomena. We use helium atoms in the metastable 23S state to enable single atom detection from ultracold atomic clouds, thereby allowing measurement of quantum statistical properties as a probe of matter-wave coherence. The inherent isolation from the atom’s surroundings also enables precision measurement of atomic structure to test quantum electrodynamics. This presentation will outline breakthroughs in both quantum physics and precision measurement enabled by such exquisite atomic control.

Kenneth Baldwin

08/09/15 - Revisiting the Morphology-Density Relation for Early Type Galaxies

Roger Davies

University of Oxford
Results on the kinematics and scaling relations of early type galaxies throw doubt on our ability to unambiguously identify disks in early type galaxies, and therefore separate elliptical and lenticular galaxies in a physical way. In contrast, velocity fields provide a clear physical distinction between galaxies on the basis of a proxy for angular momentum. These results have implications for the morphology-density relation of galaxies, and for ideas about how early type galaxies assemble. I will report new results on integral field surveys of galaxies in clusters that significantly extend the range of local densities that have been explored to test whether the morphology-density relation remains valid.

Roger Davies

29/09/15 - Archeology of Massive Galaxies

Sarah Brough

Australian Astronomical Observatory
I will present research digging up the history of the most massive galaxies in the Universe, many hundreds of times the mass of the Milky Way. Current models cannot explain their growth, but novel observations of their internal motions provide a different perspective on this puzzle, providing a new baseline for the models to reproduce.

Sarah Brough

06/10/15 - Nanodiamond: BioPhotonic and Hybrid-Photonic Applications

Brant Gibson

RMIT
Fluorescent nanodiamonds (NDs) have a range of unique properties which make them highly desirable for bioimaging and biosensing applications. Their fluorescence is produced via optical excitation of atomic defects, such as the negatively charged nitrogen vacancy centre, within the diamond crystal lattice. Possessing long-wavelength emission, high brightness, no photobleaching, no photoblinking, single photon emission at room temperature, nanometer size, biocompatibility, and an exceptional resistance to chemical degradation make NDs almost the ideal fluorescent bioimaging nanoprobe. I will discuss these exciting properties in detail and also give some examples of their integration with photonic materials for hybrid ND-biophotonic applications. In addition, I will discuss details of the research activities at the RMIT node of the ARC Centre of Excellence for Nanoscale BioPhotonics.

Brant Gibson

13/10/15 - Gas in Galaxies: The View From Cosmological Hydro-Dynamic Simulations

Claudia Lagos

ICRAR
Observations of the gas content of galaxies are becoming common place, with thousands of galaxies at a wide range of cosmic epochs being studied. This has pushed galaxy formation simulations to start addressing how the different phases of the gas inside and outside galaxies correlate with other galaxy properties, and how they evolve in the cosmological context. I will show how modern cosmological simulations of galaxy formation attempt to bring together various pieces of observational evidence, and highlight how we are treating this problem using the state-of-the-art EAGLE hydro-dynamic simulations.

Claudia Lagos

20/10/15 - Diamond Based Quantum Technologies

Fedor Jelezko

Ulm University
I will discuss recent developments transforming quantum control tools into quantum technologies based on single nitrogen-vacancy (NV) centres in diamond. I will present ultrasensitive MRI at nanoscale and recently developed magnetometry protocols that use quantum error correction as a resource. Experiments with novel colour centres including silicon-vacancy (SiV) and dinitrogen-vacancy (H3) defects will also be presented.

Fedor Jelezko - Ulm University

03/11/15 – Challenges of Fibre-Based Imaging 

Martin Ploschner

Macquarie University
Fluorescence microscopy has emerged as a pivotal platform for imaging in the life sciences. In recent years, the overwhelming success of its different modalities has been accompanied by various efforts to carry out imaging deeper inside living tissues. This is motivated by the desire to better understand cellular processes in their natural environment, fully exposed to complex interactions with the living organism they are part of. A key challenge of these efforts is to overcome scattering and absorption of light in tissues. Multiple strategies (e.g. multi-photon, wavefront correction techniques) extended the penetration depth to the current state-of-the-art of about 1000 um at the resolution of approximately 1um. The only viable strategy for imaging deeper than this is by employing a fibre bundle based endoscope. However, such devices lack resolution and have a significant footprint (1mm in diameter), which prohibits their use in studies involving e.g. the brains of live animals. 

We have recently demonstrated a radically new approach that delivers the light in/out of the place of interest through an extremely thin (tens of microns in diameter) cylindrical glass tube called a multimode optical fibre. Not only is this type of delivery much less invasive compared to fibre bundle technology, it also enables higher resolution and has the ability to image at any plane behind the fibre without any auxiliary optics. The two most important limitations of this exciting technology are (i) the lack of bending flexibility and (ii) high demands on computational power, making the performance of such systems slow. I will discuss how to overcome these limitations.

Martin Ploschner

17/11/15 – Nonequilibrium Thermodynamics of Quantum Fluids of Light

Maxime Richard

Institut Neel, Grenoble
For semiconductor optical microcavities in the so-called ‘strong-coupling regime’, the elementary excitations are cavity-photons strongly dressed by an electronic transitions, so-called quantum-well excitons. These polaritons behave very much like interacting photons. While their photonic nature provides them with a non-zero effective mass, their excitonic component leads to polariton interactions. As a result, polaritons behave like a highly dissipative quantum fluid of light. In this talk, I will first give a brief review on the superfluid properties of polaritons and the condensation phenomenon that has been demonstrated ten years ago. In the second part, I will then present recent results obtained in our group that are focused on their thermodynamical properties, showing that despite their highly nonequilibrium character, polariton fluids manage heat transport in interesting and unusual ways.

Maxime Richard

24/11/15 – Astrochemistry: Molecules in Space

Serena Viti

University College London
It is now well established that chemistry in our Milky Way, as well as in external galaxies, is rich and complex. In this talk I will give an overview of the field of Astrochemistry. I will show how molecules from our own Galaxy, as well as other galaxies, play a key role in the formation and shaping of such galaxies. By using examples from different regions of space, from interstellar and star-forming gas in the Milky Way, to extragalactic star forming regions, I will demonstrate how important molecules are for our understanding of star and galaxy formation.

Serena Viti

15/12/15 – The Puzzle of the Stellar Initial Mass Function

Andrew Hopkins

Australian Astronomical Observatory
The stellar initial mass function (IMF) describes the mass distribution of stars produced in an episode of star formation. The IMF links star formation and evolution to galaxy formation and evolution, bridging two research communities, and underpinning a broad swath of astrophysics. Surprisingly, this fundamental property is rather less well-understood than often assumed over the past sixty years. Apart from the Milky Way and a few nearby galaxies, it is not possible to measure the IMF directly through counts of resolved stars. Consequently, since it was first measured by Edwin Salpeter in 1955, the IMF has been assumed to be universal and unchanging. Studies over the past few years, though, have challenged this assumption. Numerous approaches to indirectly measure the IMF in distant galaxies provide evidence that it differs between galaxies and as a function of time, but with strongly conflicting results about the nature of the difference. I will review this recent work, and present an opportunity to self-consistently apply many of these different approaches. This opportunity exploits large-scale galaxy surveys and detailed observations within the Milky Way, combined with numerical and semi-analytic modelling, to resolve the puzzle of the IMF and provide a robust foundation to all aspects of the field of star formation in the Universe.

Andrew Hopkins

Semester 1 Talks

03/03/15 – A Classical Boy in a Quantum World

Marco Liscidini

University of Pavia
The Einstein relation between stimulated and spontaneous emission can be seen as the origin of quantum optics.  In this seminar we will show that similar relations can be found in nonlinear optics, starting with the generation of photon pairs by parametric fluorescence. This result offers a new perspective on the physics unifying classical and quantum integrated optics, and it also has important practical consequences. We will show that, by exploiting the relation between spontaneous and stimulated parametric processes, it is possible to characterize quantum correlations in photon pairs with a precision that goes well beyond the state-of-the-art of conventional tomographic approaches.

Marco Liscidini

10/03/15 – Gigantic Quantum Computers Made of Laser Light

Nicolas Menicucci

University of Sydney
Quantum computers promise ultra-fast computation, but to be useful they need to be big — really big. I will discuss recent theoretical and experimental breakthroughs in designing and building a huge quantum computer made out of laser light itself. The key component to such a quantum computer is a special type of entangled state called a continuous-variable cluster state. These states are simple to make using lasers and can be scaled up with ease to gigantic sizes. Once in possession of such a state, measurements alone enable full quantum computation, with the choice of measurements determining the computation to be performed. This is surprising because it means one can quantum compute simply by *looking* at a quantum system in a particular way. In this talk, I will describe the basics of measurement-based quantum computing using continuous-variable cluster states, including a crucial recent result showing that noise in such systems is tolerable. I will also report on their experimental realizations, including two recent demonstrations: a 60-mode cluster state and a 10,000-mode (!) cluster state. In addition to shattering world records for the number of quantum objects entangled together, these states are prototypes for the basic building block of an ultra-large-scale quantum computer.

Nicolas Menicucci

17/03/15 – What’s the Matter with Massive Galaxies?

Richard McDermid

Macquarie University
Mass is a basic property of galaxies that is fundamental to understanding the ways in which galaxies form and evolve. However, accurate measurements of galaxy mass are complicated by the combined effects of dark matter, galaxy structure and stellar population uncertainties. The situation has recently improved thanks to new observational efforts to disentangle these components. Specifically, I will focus on recent results from the Atlas3D Survey: a multi-wavelength census of massive galaxies in the nearby universe.

Richard McDermid

24/03/15 – Can We Achieve the Ultimate in Laser Machining: Selective Atom Removal?

Richard Mildren

Macquarie University
An optical method of selectively breaking bonds on surfaces has been a long sought after goal in the field of light-matter interactions. Our recent observations show that UV irradiated diamond surfaces may be one of the few systems in nature that exhibit such selectivity, along with accompanying ejection of carbon. This talk will describe a range of curious observations that characterize this process, its potential applications in device fabrication and our attempts to understand the obscure mechanism.

Richard Mildren

31/03/15 – Massive Stellar Surveys

Sarah Martell

University of New South Wales
In this talk I will discuss the science, strategy and sociology of large astronomical survey collaborations, using the Galactic Archaeology with HERMES (GALAH) Survey as an example. GALAH is a major ongoing observational project at the Anglo-Australian Telescope that will determine stellar parameters and abundances for 1 million stars in the Milky Way, and then use that information to explore the history of star formation, chemical enrichment, minor mergers and stellar migration in the Milky Way. The science capabilities of GALAH and other planned and ongoing Galactic Archaeology surveys are driven by choices in instrument design and survey strategy. I will describe several of the research topics that can be explored by these large surveys, and how they connect to other areas of astronomy.

Sarah Martell

28/04/15 – Can We Find ET on a Chip?

Peter Tuthill

University of Sydney
The planets in our own solar system were discovered by direct observation of planetary light (the brightest known since antiquity by naked eye, to which an ever expanding list of outer solar system bodies is being added by large telescopes and missions). Interestingly, when it comes to planets in orbit around distant stars, such a straightforward approach – searching for faint flecks of light next to stars – turns out to be extremely difficult. Exoplanetary catalogues are overwhelming filled with discoveries made by indirect techniques of radial velocity or stellar transits. However, despite the daunting technological challenge posed by direct imaging techniques, there are excellent reasons to persist with it. Physically separating stellar from planetary light reveals spectra of planetary atmospheres and surfaces, and paves the way for visionary observatories of tomorrow capable of prospecting for habitable biospheres on distant worlds. This talk will describe a very active collaboration between the Universities of Sydney and Macquarie to pioneer new technologies capable of addressing these inspiring themes.

Peter Tuthill

05/05/15 – From the Solar Nebula to the Deep Earth

Bill Griffin

Macquarie University
Geology is a great research field; it can take you on strange journeys. In the mountains of southern Tibet, large massifs (≥1000 k3) of ultramafic rocks, fragments of Earth’s mantle, contain mineral assemblages that require both exhumation from very great depths (>500 km down) and extremely low oxygen fugacity (reducing conditions) not ordinarily expected within the mantle. To learn the story of these remarkable rocks, we have had to investigate both the mechanisms that have brought them up to the surface, and the origins of super-reducing conditions in the mantle. This has involved field studies, geodynamic modelling, a range of techniques for micron-scale chemical, microstructural and isotopic analysis, and a bit of good luck. One of the keys to the Tibetan riddles lies near the Sea of Galilee in Israel, and involves a remarkable, still poorly-understood type of volcanic activity. The colloquium will try to lead you through this story, which is still evolving by the day, and to illustrate the diversity of approaches required in modern geological research.

Bill Griffin

12/05/15 – Quantum Devices to Quantum Machines: Engineering the Scale-up of Quantum Technology

David Reilly

University of Sydney
There is currently widespread belief that the building-blocks of quantum machines have been established. The game now is to combine and scale-up these individual components into complex, fault-tolerant quantum systems. This talk will present a perspective on the challenges of scaling-up quantum devices and highlight work underway at the University of Sydney to engineer quantum machines from semiconductor systems.

David Reilly

02/06/15 – High-End Amateur Astrophotography: Things That Go Bump In The Night

Mike Berthon-Jones

ResMed Consultant and Amateur Astronomer
In this talk I will present a visual atlas of what armchair astrophysics, and beauty, can be seen in action using a top-end 20 inch reflector and a dedicated astrocamera, with special emphasis on narrowband imaging. After a whirlwind tour of constructing a personal observatory, I will present and discuss a selection of images I have personally taken of various night-sky objects, from star clusters to galaxies, the birth and death of stars, and a walk through star-forming regions in our galaxy and in the Magellanic Clouds. Example images can be found here.

Mike Berthon Jones
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