Research Interests

¿ My research is mainly concerned with the quantum theory of condensed-matter systems, i.e., with solids and also with quantum fluids such as liquid helium. Studies are being carried out for the dynamical properties in terms of the excitations (or quantized waves) that can propagate in these systems. Examples are phonons in crystalline solids, magnons (or spin waves) in magnetic materials, plasmons in metals and semiconductors, and polaritons formed by the coupling of the above crystal excitations to photons (or light).

¿ The emphasis of the present work is directed towards understanding the properties of nanostructures and other low-dimensional structures where the influence of surfaces and interfaces becomes predominant and new phenomena can emerge. Some simple examples are thin films and multilayers, where the films can be arranged in a periodic sequence to form a superlattice. Other examples are quasiperiodic multilayers (which have interesting fractal properties), patterned surfaces, and nanowire arrays, etc. Also, in these low-dimensional structures, the nonlinear properties can become important, giving rise to novel physical features (such as the formation of soliton-like waves) which are of potential importance for device applications.

¿ The above research involves using analytical methods, such as many body theory and quantum field theory (including, for example, Feynman diagram methods) on the one hand and numerical simulations (e.g. Monte-Carlo techniques) on the other, as appropriate. Applications are made to various experimental methods, including Raman and Brillouin light scattering, scattering of particle beams, microwave and infrared spectroscopies, etc.

¿ I would be pleased to provide more information about my current work in any of the above areas. Also I am involved in interdisciplinary, collaborative work on biological systems (e.g. analytical theories and numerical simulations for electron transport and photosynthesis in plants).

¿ To send me an email click cottam@uwo.ca. You are also welcome to contact me if you wish to inquire about research collaborations or about research opportunities as graduate students (at the M.Sc. or Ph.D. levels) or as post-docs.

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