Ab initio calculation of valley splitting in monolayer δ-doped phosphorus in silicon

• Published in: Nanoscale research letters Vol. 8; no. 1; p. 111
• Main Authors: Drumm, Daniel W, Budi, Akin, Per, Manolo C, Russo, Salvy P, L Hollenberg, Lloyd C
• Format: Journal Article
• Language: English
• Published: New York Springer New York 27.02.2013; BioMed Central Ltd; Springer
• Subjects: Chemistry and Materials Science; Materials Science; Molecular Medicine; Nano Express; Nanochemistry; Nanoscale Science and Technology; Nanotechnology; Nanotechnology and Microengineering; 73.22.-f; Phosphorus in silicon; Valley splitting; 71.15.Mb; Density functional theory; 31.15.ae; Basis sets; Doped layers
• ISSN: 1931-7573; 1556-276X; 1556-276X
• DOI: 10.1186/1556-276X-8-111

The differences in energy between electronic bands due to valley splitting are of paramount importance in interpreting transport spectroscopy experiments on state-of-the-art quantum devices defined by scanning tunnelling microscope lithography. Using vasp , we develop a plane-wave density functional theory description of systems which is size limited due to computational tractability. Nonetheless, we provide valuable data for the benchmarking of empirical modelling techniques more capable of extending this discussion to confined disordered systems or actual devices. We then develop a less resource-intensive alternative via localised basis functions in siesta , retaining the physics of the plane-wave description, and extend this model beyond the capability of plane-wave methods to determine the ab initio valley splitting of well-isolated δ -layers. In obtaining an agreement between plane-wave and localised methods, we show that valley splitting has been overestimated in previous ab initio calculations by more than 50%.