ERC FUNDED PROJECTS

Nanowires based on group III–nitride semiconductors exhibit outstanding potential for emerging applications in energy-efficient lighting, optoelectronics and solar energy harvesting. Nitride nanowires, tailored at the nanoscale, should overcome many of the challenges facing conventional planar nitride materials, and also add extraordinary new functionality to these materials. However, progress towards III–nitride nanowire devices has been hampered by the challenges in quantifying nanowire electrical properties using conventional contact-based measurements. Without reliable electrical transport data, it is extremely difficult to optimise nanowire growth and device design. This project aims to overcome this problem through an unconventional approach: advanced contact-free electrical measurements. Contact-free measurements, growth studies, and device studies will be cross-correlated to provide unprecedented insight into the growth mechanisms that govern nanowire electronic properties and ultimately dictate device performance. A key contact-free technique at the heart of this proposal is ultrafast terahertz conductivity spectroscopy: an advanced technique ideal for probing nanowire electrical properties. We will develop new methods to enable the full suite of contact-free (including terahertz, photoluminescence and cathodoluminescence measurements) and contact-based measurements to be performed with high spatial resolution on the same nanowires. This will provide accurate, comprehensive and cross-correlated feedback to guide growth studies and expedite the targeted development of nanowires with specified functionality. We will apply this powerful approach to tailor nanowires as photoelectrodes for solar photoelectrochemical water splitting. This is an application for which nitride nanowires have outstanding, yet unfulfilled, potential. This project will thus harness the true potential of nitride nanowires and bring them to the forefront of 21st century technology.

1 499 195 €

Start date: 2017-04-01, End date: 2022-03-31

I propose a program of research that may forever change the way that we understand and use quantum field theory to make predictions for experiment. This will be achieved through the advancement of new, constructive frameworks to determine and represent scattering amplitudes in perturbation theory in terms that depend only on observable quantities, make manifest (all) the symmetries of the theory, and which can be efficiently evaluated while minimally spoiling the underlying simplicity of predictions. My research has already led to the discovery and development of several approaches of this kind. This proposal describes the specific steps required to extend these ideas to more general theories and to higher orders of perturbation theory. Specifically, the plan of research I propose consists of three concrete goals: to fully characterize the discontinuities of loop amplitudes (`on-shell functions') for a broad class of theories; to develop powerful new representations of loop amplitude {\it integrands}, making manifest as much simplicity as possible; and to develop new techniques for loop amplitude {integration} that are compatible with and preserve the symmetries of observable quantities. Progress toward any one of these objectives would have important theoretical implications and valuable practical applications. In combination, this proposal has the potential to significantly advance the state of the art for both our theoretical understanding and our computational reach for making predictions for experiment. To achieve these goals, I will pursue a data-driven, `phenomenological' approach—involving the construction of new computational tools, developed in pursuit of concrete computational targets. For this work, my suitability and expertise is amply demonstrated by my research. I have not only played a key role in many of the most important theoretical developments in the past decade, but I have personally built the most powerful computational tools for their

1 499 695 €

Start date: 2018-02-01, End date: 2023-01-31

"This proposal addresses major questions in particle physics that are at the forefront of experimental and theoretical physics research today. The results offered would have far-reaching implications in other fields such as cosmology and could help answer some of the big questions such as why the universe contains so much more matter than antimatter. The research objectives of this proposal are to (i) make world-leading tests of CPT symmetry and (ii) discover the neutrino mass hierarchy and search for indications of leptonic CP violation. The NOvA long-baseline neutrino oscillation experiment will use a novel ""totally active scintillator design"" for the detector technology and will be exposed to the world's highest power neutrino beam. Building on the first direct observation of muon antineutrino disappearance (that was made by a group founded and led by the PI at the MINOS experiment), tests of CPT symmetry will be performed by looking for differences in the mass squared splittings and mixing angles between neutrinos and antineutrinos. The potential to discover the mass hierarchy is unique to NOvA on the timescale of this proposal due to the long 810 km baseline and the well measured beam of neutrinos and antineutrinos. This proposal addresses several key challenges in a long-baseline neutrino oscillation experiment with the following tasks: (i) development of a new approach to event energy reconstruction that is expected to have widespread applicability for future neutrino experiments; (ii) undertaking a comprehensive calibration project, exploiting a novel technique developed by the PI, that will be essential to achieving the physics goals; (iii) development of a sophisticated statistical analyses. The results promised in this proposal surpass the sensitivity to antineutrino oscillation parameters of current 1st generation experiments by at least an order of magnitude, offering wide scope for profound discoveries with implications across disciplines."

1 415 848 €

Start date: 2012-10-01, End date: 2018-09-30

The objective of the BEACON project is to (re-)introduce analog communications into the design of modern wireless networks. We argue that the extreme energy and latency constraints imposed by the emerging Internet of Everything (IoE) paradigm can only be met within a hybrid digital-analog communications framework. Current network architectures separate source and channel coding, orthogonalize users, and employ long block-length digital source and channel codes, which are either suboptimal or not applicable under the aforementioned constraints. BEACON questions these well-established design principles, and proposes to replace them with a hybrid digital-analog communications framework, which will meet the required energy and latency constraints while simplifying the encoding and decoding processes. BEACON pushes the performance of the IoE to its theoretical limits by i) exploiting signal correlations that are abundant in IoE applications, given the foreseen density of deployed sensing devices, ii) taking into account the limited and stochastic nature of energy availability due to, for example, energy harvesting capabilities, iii) using feedback resources to improve the end-to-end signal distortion, and iv) deriving novel converse results to identify fundamental performance benchmarks. The results of BEACON will not only shed light on the fundamental limits on the performance any coding scheme can achieve, but will also lead to the development of unconventional codes and communication protocols that can approach these limits, combining digital and analog communication techniques. The ultimate challenge for this project is to exploit the developed hybrid digital-analog networking theory for a complete overhaul of the physical layer design for emerging IoE applications, such as smart grids, tele-robotics and smart homes. For this purpose, a proof-of-concept implementation test-bed will also be built using software defined radios and sensor nodes.

1 496 350 €

Start date: 2016-10-01, End date: 2021-09-30