Regensburg 2016 – wissenschaftliches Programm
HL 73.12: Vortrag
Donnerstag, 10. März 2016, 12:45–13:00, H17
Ab initio Anderson localisation in Si:P — •Edoardo G. Carnio1, Nicholas D. M. Hine1, David Quigley1,2, and Rudolf A. Römer1,2 — 1Department of Physics, The University of Warwick, Coventry CV4 7AL, UK — 2Centre for Scientific Computing, The University of Warwick, Coventry CV4 7AL, UK
The Anderson metal-insulator transition (MIT) has long been studied, but there is still no agreement on its critical exponent when comparing experiments and theory. In this work, we employ ab initio methods to study the MIT that occurs in phosphorus-doped silicon (Si:P) when the density of the dopants is increased. Our strategy consists in using ONETEP, an implementation of linear scaling DFT, to model an effective potential between the P atoms, which is used in a Monte Carlo simulation to randomly distribute the impurities in the host material. We then combine these spatial configurations with the DFT data into an effective tight-binding Hamiltonian for a system of Si:P close to the critical concentration of the MIT. In this way we characterise the MIT in Si:P including the ab initio determined possible spatial correlations in P and the electronic interactions between the donated electrons. The extent of the resulting electronic states is characterised by the participation numbers and their scaling.