Positrons are the antimatter version of electrons and so their fate in a matter world is ultimately to annihilate. However, prior to this, a positron may combine with an electron to form a matter-antimatter hybrid called positronium. This is akin to a hydrogen atom with the proton replaced by a positron. Fundamental to our understanding of the physical universe, positron and positronium are these days also acknowledged as being fantastically useful in practical applications such as probing material properties and medical diagnostics. However, there is still much that we do not know for sure about the details of the interactions of these particles with ordinary matter. For example if, in a collision with an atom or molecule, a positron captures an electron, in which directions is the positronium likely to travel and with what probability? More...
Published: Jun 17, 2015 12:35:19 PM
How light of different colours is absorbed by carbon dioxide (CO2) can now be accurately predicted using new calculations developed by a UCL-led team of scientists. This will help climate scientists studying Earth’s greenhouse gas emissions to better interpret data collected from satellites and ground stations measuring CO2. More...
Published: Jun 15, 2015 10:29:10 AM
New research from UCL has uncovered additional second laws of thermodynamics which complement the ordinary second law of thermodynamics, one of the most fundamental laws of nature. These new second laws are generally not noticeable except on very small scales, at which point, they become increasingly important. More...
Published: Feb 10, 2015 11:55:53 AM
Dr Carla Figueira de Morisson Faria
My research website: click here
Dr Carla Faria graduated in Physics at the University of Sao Paulo, Brazil, where she also worked with Professor Vanderlei Bagnato on cooling and trapping of neutral atoms. Subsequently, she did her Ph.D. at the Max Born Institut, Berlin, under the supervision of Professor Wolfgang Sandner and Dr Martin Dörr, on the Interaction of Atoms with Intense Laser Fields and Ultrashort Pulses. Thereafter, she was a postdoctoral researcher at the Max Planck Institute for Physics of Complex Systems, Dresden (1999-2001), the MBI-Berlin (2002-2003), the Technical University Vienna (2002) and the University of Hanover (2003-2004). In 2005, she moved to the UK as a University Research Fellow at the Centre for Mathematical Sciences, City University, London, where she became a Lecturer in 2006. Since April 2007, she has joined the University College London as a Lecturer. Dr Faria has also been awarded an EPSRC Advanced Research Fellowship in October 2006.
Dr Faria is a specialist on theoretical strong-field laser-matter interaction. Since the mid-1990s, she has been developing theoretical models for several phenomena in this context, using both analytical and numerical methods. Dr Faria has around 40 publications in this research area, in peer-reviewed journals and conference proceedings, and has participated in several conferences in Optical Physics, in many of which as an invited speaker. She is also a referee for several optics journals (Physical Review Letters, Optics Communications, JOSA B, Journal of Modern Optics, Optics Letters and Journal of Physics B), and has various collaborations with leading groups in the field. She also actively collaborates with scientists of other research areas, such as quantum optics and mathematical physics. Ongoing collaborations include Professor Andreas Fring (City University), the theory and experimental groups at the MBI-Berlin, Professor Maciej Lewenstein (Institute for Photonic Sciences, Barcelona), Professor Anna Sanpera (Universidad Autonoma, Barcelona), Dr Henning Schomerus (Lancaster University), Professor Jon Marangos (Imperial College), and Professor Ingrid Rotter (Max Planck Institut, Dresden).
The interaction of matter with laser fields of the order of or stronger than 1013W/cm2 has posed a formidable challenge to theorists within atomic, molecular and optical physics for a very simple reason. Up to the mid-1980s, when strong lasers became feasible, laser-matter interaction could be successfully described by taking the field as a perturbation. Such an approach, however, breaks down in the strong-field regime. As a direct consequence, our physical intuition concerning optical phenomena, which has been built upon perturbation theory with the laser field, needs to be re-evaluated. Furthermore, in order to treat such phenomena adequately, alternative theoretical methods are necessary.
Apart from its fundamental value as an area of science, strong-field laser physics has a wide range of applications, such as particle physics, plasma physics (in particular laser fusion), solid-state physics, novel X-ray sources, and attosecond science. In particular, attosecond science is an emerging, interdisciplinary field of research, in which the fact that most strong-field phenomena take place in the attosecond (10-18s) time range plays a very important role. Hundreds of attoseconds are roughly the time it takes for light to travel through atomic distances. Hence, such phenomena can be used as tools to resolve, or even control, dynamic processes at the atomic scale. Concrete examples are the motion of bound electrons, or electron emission.
Current research interests
- Correlated multielectron processes in strong laser fields (laser-induced nonsequential double and multiple ionization)
- Attosecond pulses
- Attosecond control of matter
- Applications of high-order harmonic generation and above-threshold ionization
- Molecules in intense laser fields
- Non-Hermitian Hamiltonian systems
Page last modified on 08 mar 11 23:38