Research Areas
My research interests lie mainly in the field of theoretical nuclear physics. This has mostly been in the development of few-body quantum scattering methods to study nuclear reaction mechanisms and nuclear structure, particularly as applied to the study of exotic nuclei produced by radioactive beam facilities around the world. I have pioneered the application of few-body Glauber methods in nuclear scattering and reactions at intermediate and high energies. My interests span a wide range of reaction energies from the study of the light nuclei using electromagnetic probes such as electron scattering and photo-induced pion production reactions, to reactions of astrophysical interest. Over the past few years I have become interested in decay studies of exotic nuclei and proton radioactivity.
A new area I am interested in open quantum systems, particularly in biology. Quantum biology is a relatively new area but there are some interesting questions. Many processes in microbiology can be reduced down to chemical physics and, ultimately, to molecular and atomic processes such as quantum tunnelling. For instance, certain genetic mutations take place when a hydrogen bond is broken between two base pairs in the DNA and a new adjacent bond is made. This has been successfully described in terms of a proton quantum tunnelling between two potential wells. But the field is still relatively new and there are many fascinating problems that need to be addressed. Chief among these is the issue of the effect of the quantum system’s external environment (within the cell), which acts as a thermal bath and the coupling to which causes dissipation and decoherence. To capture the essence of the dissipative quantum dynamics of this process, Meyer and Ernst [1] developed one- and two-dimensional models to describe such a system, and at the same time proposed a microscopic model for its coupling to a heat bath, idealised as a set of harmonic oscillators. One way to include this physics is to solve the time-dependent Liouville equation for the density matrix including a so-called Lindblad term, which has been studied in biological systems by Scheuer and Saalfrank [2]. Sophisticated numerical techniques for solving such a time-dependent equation for the density matrix have been used by Stevenson in his nuclear structure research for a number of years.
A new research project aims at building on work in solving the Liouville-Lindblad equation for tunnelling of a wave packet through a potential barrier. What is not known is the extent to which dissipative process due to coupling to the environment can lead to other quantum processes such as the Zeno effect [3] and its associated anti-Zeno effect [4] and how these can influence the tunnelling rate. We have shown already that this can lead to interesting effects [5,6].
[1] R Meyer and R R Ernst, J. Chem. Phys, 93, 5518 (1990).
[2] C Scheurer and P Saalfrank, J. Chem. Phys, 104, 2869 (1996).
[3] E C G Sudarshan and B Misra, J Math. Phy. 18, 756 (1977).
[4] H Fearn and W Lamb, Phys. Rev. A 46, 1199 (1992).
[5] J S Al-Khalili and P D Stevenson, Adv. Sci. Lett. 1, 140 (2008).
[6] J MacFadden and J S Al-Khalili, BioSystems 50, 203 (1999).
- Editor of three nuclear physics textbooks and contributing author in two others.
- 67 publications in peer reviewed journals
- >30 invited talks at national and international conferences and workshops
- >40 invited external research seminars and colloquia
- Over 120 conference papers in nuclear physics