< Previous48 ARC CENTRE OF EXCELLENCE IN FUTURE LOW-ENERGY ELECTRONICS TECHNOLOGIES LONG-LIVED ‘SQUEEZED’ NANOLIGHT DISCOVERED IN 2D MATERIAL Quantum breakthrough could deliver new ultra-low- energy electronics and communications technology An international collaboration led by FLEET’s A/Prof Qiaoliang Bao (Monash University) used ‘squeezed’ light to make a significant quantum breakthrough. In a world-first, the team observed a difference in the physical and mechanical properties of polaritons moving along the surface of a van der Waals (vdW) material in different directions. Polaritons are a ‘hybrid’ particle, which can trap and manipulate light within micrometre-scale structures, while vdW materials are composed of multiple layers of two-dimensional (2D) structures. The study found that squeezed light (nanolight) propagates only in specific directions along thin slabs of 2D molybdenum trioxide. This nanolight also lives for an exceptionally long time, and thus could find applications in signal processing, sensing or heat management at the nanoscale. Squeezing (confining) light to such a small size has been a major goal in nanophotonics for many years. The structure of molybdenum trioxide is distorted by vdW interactions. Near-field optical microscopy is a new method allowing improved imagery of polaritons. A successful strategy has been the use of polaritons, which are electromagnetic waves resulting from the coupling of light and matter. Particularly strong light squeezing can be achieved with polaritons at infrared frequencies in certain 2D materials. However, polaritons in other materials have always been found to propagate along all directions of the material surface, thereby losing energy quite fast and limiting their usefulness. Recently, it was predicted that polaritons could propagate ‘anisotropically’ along the surface of 2D materials (ie, their propagation was different in different directions). In this case, the velocity and wavelength of the polaritons strongly depend on the direction in which they propagate. This property can lead to highly-directional polariton propagation in the form of nanoscale confined rays, which could find future applications in the fields of sensing, thermal heat management or maybe even quantum computing. In addition to directional propagation, the study also revealed that the polaritons in this test material can have an extraordinarily long lifetime. Light seems to take a nanoscale ‘highway’, travelling in some directions with almost no obstacles. Polaritons were observed to live 40 times longer than the best similar measurements in graphene. Researchers used a new microscope technique known as near-field optical microscopy, which has emerged alongside novel vdW materials over the past few years, to allow imaging of a variety of unique and even unexpected polaritons. CASE STUDY49 FLEET 2018 ANNUAL REPORT The current work is just the beginning of a series of studies focused on directional control and manipulation of light with the help of ultra-low-loss polaritons at the nanoscale. This work could benefit the development of more efficient nanophotonic devices for optical sensing and signal processing or thermal heat management. Within FLEET, A/Prof Bao investigates waveguide- coupled 2D semiconductors and plasmon-coupled 2D materials and devices, focusing on the effect of confined- space light-matter interactions on the transport of electrons or other quasi-particles such as polaritons. This addresses FLEET milestone 1.2; see p93. The study was published in Nature in October 2018, vol. 562 (see publication 26, p105) . COLLABORATING FLEET PERSONNEL: • Research Fellow Zhigao Dai (Monash) • Alumnus Yupeng Zhang (now at Shenzhen University) • Chief Investigator Kourosh Kalantar-zadeh (UNSW/RMIT) • Chief Investigator Qiaoliang Bao (Monash) Collaboration with different research groups is crucial to develop and further improve our capabilities, incorporating new areas of expertise such as materials growth, device fabrication or analytical investigations. A/Prof Qiaoliang Bao FLEET Chief Investigator, Monash University FLEET's Qiaoliang Bao (Monash Engineering) uses cutting-edge microscope technology at the Australian National Fabrication Facility (ANFF), where he is a Technical Fellow. More at FLEET.org.au/polariton-breakthrough50 ARC CENTRE OF EXCELLENCE IN FUTURE LOW-ENERGY ELECTRONICS TECHNOLOGIES PUSHING PRINT ON LARGE-SCALE PIEZOELECTRICS First ever large-scale 2D surface deposition of piezoelectric material — this simple, inexpensive technique opens new fields for piezo-sensors and energy harvesting In 2018, FLEET researchers developed a revolutionary method to ‘print’ large-scale sheets of two-dimensional (2D) piezoelectric material, opening up new opportunities for piezo-sensors and energy harvesting. Piezoelectric materials produce a small voltage when put under stress, and form the key component of ultra- sensitive pressure sensors, such as the motion-detectors in smartphones. Importantly, this new, inexpensive fabrication process allows piezoelectric components to be directly integrated onto silicon chips, which has not previously been possible. This will significantly reduce manufacturing costs. Now, FLEET researchers at RMIT University have demonstrated a method to produce large-scale 2D gallium phosphate sheets that allows this material to be formed at large scales in low-cost, low-temperature manufacturing processes onto silicon substrates, or any other surface. The material used, gallium phosphate (GaPO 4 ), is particularly useful in high temperatures or other harsh environments. CASE STUDY PhD student Nitu Syed and FLEET AI Dr Torben Daeneke (RMIT).51 FLEET 2018 ANNUAL REPORT The revolutionary new method allows easy, inexpensive growth of large-area (several centimetres), wide- bandgap, 2D GaPO 4 nanosheets. The new process is simple, scalable, low temperature and cost-effective, significantly expanding the range of materials available to industry at such scales and quality. This simple, industry-compatible procedure to print large- surface-area 2D piezoelectric films onto any substrate offers tremendous opportunities for the development of piezo-sensors and energy harvesters. Piezoelectric materials can convert applied mechanical force or strain into electrical energy. Such materials form the basis of sound and pressure sensors, embedded devices that are powered by vibration or bending, and even the simple ‘piezo’ lighter used for gas BBQs and stovetops. Piezoelectric materials can also take advantage of the small voltages generated by tiny mechanical displacement, vibration, bending or stretching to power miniaturised devices. Test materials were synthesised in RMIT’s Micro Nano Research Facility (MNRF). This addresses FLEET milestone 1.1; see p93. The study was published in Nature Communications in September 2018, vol. 9 (see publication 40, p105). COLLABORATING FLEET PERSONNEL: • Research Fellow Ali Zavabeti (RMIT) • Associate Investigator Jian-zhen Ou (RMIT) • Alumnus Ben Carey (now at University of Munster) • Associate Investigator Torben Daeneke (RMIT) • Chief Investigator Kourosh Kalantar-zadeh, (UNSW/RMIT) As so often in science, this work builds on past successes. We adopted the liquid-metal material deposition technique we developed recently to create the 2D films. Dr Torben Daeneke FLEET Scientific Associate Investigator, RMIT These types of discoveries show that the benefits of discovery- based research extend beyond FLEET’s focused objectives, and will have impacts in a diverse range of fields. Prof Michael Fuhrer FLEET Director FLEET has developed new, inexpensive methods for fabrication of useful 2D materials using liquid metals such as gallium. More at FLEET.org.au/piezoelectricFLEET Research Fellow Dr Sam Bladwell (UNSW) and visiting AI A/Prof Shaffique Adams (National University of Singapore). FLEET draws on leading national and international experts to fulfil the Centre’s mission. COLLABORATE 0 3 53 FLEET 2018 ANNUAL REPORT 134 VISITS BY INTERNATIONAL COLLABORATORS 4 INTERNATIONAL TRIPS MADE FOR RESEARCH COLLABORATION 11 FLEET MEMBERS VISITING PARTNER ORGANISATIONS 41 VISITS BY INTERNATIONAL STUDENTS AND ECRs NEW ORGANISATION LINKS FOR TRAINING AND OUTREACH ESTABLISHED NEW RESEARCH COLLABORATING ORGANISATIONS ESTABLISHED END-USER RELATIONSHIPS ESTABLISHED 12 4 19 FLEET has transformed my scientific career. Working and collaborating and exchanging ideas with diverse people within FLEET motivates my research work and as I continue in FLEET I will continue to learn and grasp more knowledge. Dr Shilpa Sanwlani FLEET Research Fellow, Swinburne54 ARC CENTRE OF EXCELLENCE IN FUTURE LOW-ENERGY ELECTRONICS TECHNOLOGIES RESEARCH COLLABORATION - Wroclaw University of Science and Technology (WUST) is Poland’s top-ranked new-technology university, excelling in computer science, electronics and material science. FLEET’s new Partner Investigator Prof Grzegorz Sek, who specialises in nanophotonics, two-dimensional (2D) materials and exciton-polariton condensation, will work closely with FLEET CI Prof Ostrovskaya (ANU). The Beijing Computational Science Research Center (CSRC) in China is a multidisciplinary, fundamental- research organisation undertaking computational science and condensed-matter research. FLEET’s new Partner Investigator, CSRC Director Prof Hai-Qing Lin, coordinates collaborations with FLEET’s Dr Dimi Culcer (UNSW), developing advanced new theoretical and computational techniques for studying topological phenomena. NEW RESEARCH PARTNERS In 2018, FLEET added three new partner organisations and five new Partner Investigators, expanding on existing research relationships and leveraging shared expertise. These new agreements bring FLEET’s Australian and international partners to 16 (see chart below).55 FLEET 2018 ANNUAL REPORT The University of Camerino in Italy has had a dynamic and successful research partnership with FLEET researchers, now formalised via a partnership agreement. The University’s Prof Andrea Perali and Prof David Neilson join FLEET as new Partner Investigators, studying the theory of exciton superfluids with FLEET CI Prof Alex Hamilton (UNSW) (see exciton case study p30) . FLEET’s fruitful relationship with Tsinghua University in Beijing, China, has expanded, with the Centre welcoming two new Partner Investigators to lead research collaborations. Prof Shuyun Zhou studies the electronic structure of novel 2D materials and heterostructures using advanced electron spectroscopic tools, and will work closely with Prof Michael Fuhrer (Monash University) on 2D deposition. Prof Pu Yu studies emergent phenomena at the interface of correlated electron systems and will work closely with Profs Xiaolin Wang (UOW) and Nagy Valanoor (UNSW) on ferroelectrics. EXPLORING POTENTIAL LINKAGES: NEW ZEALAND’S MACDIARMID INSTITUTE community and media to issues around information and communication technology (ICT) energy use and ultra-low-energy electronics. In return, five senior MacDiarmid researchers spoke at the FLEET annual workshop and at ICON-2DMat, introducing all FLEET members to leading nanotechnology and beyond-CMOS electronics research. In 2018, FLEET strengthened its links with leading New Zealand nanotechnologists via the MacDiarmid Institute, the country’s leading nanotechnology and materials research organisation. FLEET Director Prof Michael Fuhrer spoke at Materialise, the sustainable materials science event hosted by the Institute, introducing the NZ science FLEET Director Michael Fuhrer featured in an online game to engage the public with sustainable-materials science.56 ARC CENTRE OF EXCELLENCE IN FUTURE LOW-ENERGY ELECTRONICS TECHNOLOGIES CONNECTING GLOBAL RESEARCHERS ICON-2DMAT 2018 MELBOURNE CONVENTION & EXHIBITION CENTRE, MELBOURNE AUSTRALIA 4 TH INTERNATIONAL CONFERENCE ON TWO-DIMENSIONAL MATERIALS AND TECHNOLOGIES 10-13 Dec 2018 HOSTING INTERNATIONAL 2D MATERIALS CONFERENCE FLEET hosted the International Conference on Two-Dimensional Materials and Technologies (ICON-2DMat) in Melbourne in December 2018. This was the first time ICON-2DMat had been held in Australia, and with around 300 international and Australian delegates attending, it was an opportunity to showcase the strength of atomically-thin materials research in Australia. Attendance at the international conferences on 2D materials is growing, reflecting rising interest in the useful electronic, opto-electronic and material properties of atomically-thin materials. Scientific journal editorial panel, ICON-2DMat. FLEET Director Prof Michael Fuhrer.57 FLEET 2018 ANNUAL REPORT ICON-2DMat 2018 connected FLEET and other leading Australian 2D scientists with top international experts to discuss the latest research and emerging applications. The international and Australian delegates enjoyed six plenary talks, 16 keynote talks, 148 oral presentations and over 90 poster presentations. Free, on-site childcare was provided, paid for by the conference’s sponsors and demonstrating FLEET’s commitment to leadership in family-friendly conferences (see p63) . Recognising excellence, ECR poster sessions and networking, ICON-2DMat. More information FLEET.org.au/ICON2DMATNext >