Research in the Theory Group


Rajat K. Bhaduri Melvin A. Preston
Cliff Burgess Donald W.L. Sprung
Yukihisa Nogami Wytse van Dijk


Members of the theory group have varied interests and while they work on different topics, they tend to use similar general techniques in their work. The efforts in theoretical astrophysics and theoretical condensed matter physics are described under those headings. A wide range of more general theoretical investigations are ongoing within the department.

Bhaduri is broadly interested in the connection between quantum theory and classical periodic orbits in non-integrable dynamical systems. He also works on low-dimensional physics and quantum statistics, including Bose-Einstein condensation of dilute gases in traps.

Burgess is a high-energy particle theorist whose current interests lie at the interface between string theory and lower-energy physics, with a particular emphasis on how the discovery of D-branes (and the realization that we may be trapped on one) may have observable consequences in experiments and in cosmology.

Nogami has been interested in the propagation of wave packets and solitons in nonrelativistic as well as relativistic quantum mechanics. With van Dijk, he has been studying quantum tunnelling of wave packets through potential barriers. This has led to applications on the alpha decay problem in nuclei. Nogami's other work relates to the field theoretical description of the vacuum in relation to fractional fermion numbers. van Dijk and Sprung also study two-nucleon scattering, and its implications on the nuclear force.

Preston has been active recently in the area of quantisation under constraints, and applied the theory to topological solitons. The correct procedure leads to the stability of the Skyrmion with a simpler Lagrangian, and a consistent description of the nucleon.

Sprung, in collaboration with Hua Wu and J. Martorell (Barcelona) has been interested in nanometer scale electron devices. They have studied electron transport through quantum wires with a variety of bends and cavities attached to them, and have developed an elegant formalism for scattering in a finite periodic system. Electron confinement in heterostructures has been studied using the self-consistent Thomas Fermi method. Through the QUADRANT project, funded through the European Union, the group has been attempting to implement the Quantum Cellular Automaton (QCA) paradigm in semiconductor materials using analytical as well as computational methods.