B5.

Project title: Development of accurate theory to simulate large system at atomistic level

Problems in condensed matter physics and materials science generally involve a large amount of atoms. This leads to the computations of large systems to do atomistic simulations for materials design or understanding. In using the existing first-principle theories, even with the most sophisticated computational facilities presently available, the systems, which could be handled, are still too small in size. Whereas, if empirical or semi-empirical approaches are used , the achieved accuracy is frequently not sufficient for solving the specific problems. For more efficient, reliable and accurate computations, it is necessary to develop a more advanced theoretical approach for the many-body systems.

According to a general approach proposed in hyperspherical coordinates, the Schr?inger equation for a quantum-mechanical many-body system could be solved without using any approximation [R.Q. Zhang and C.H. Deng, Physical Review A, 47(1), 71(1993)]. This approach has found successful applications in small systems including atoms [see, e.g. R.Q. Zhang Int. J. Quantum Chemistry, 59, 203(1996) and references therein] and charged excitons in quantum wells [W.Y. Ruan, K.S. Chan, H.P. Ho, R.Q. Zhang, and E.Y.B. Pun, Phys. Rev. B 60, pp. 57 14-5720(1999)]. In this proposed research, further development of the said approach to systems involving large number of electron and nuclei will be pursued. The theory to be developed will find wider applications not only in condensed matter physics and materials science but also in all areas where microscopic processes take effect.

Supervisor: Prof R Q Zhang (aprqz@cityu.edu.hk)

Suitable for: Ph.D.