https://doi.org/10.1140/epjb/e2011-20804-7
Regular Article
Theoretical studies on intervalley splittings in Si/SiO2 quantum dot structures
1
Department of Electronics Engineering, Catholic University of
Daegu, Hayang,
712-702
Kyeongbuk, Republic of
Korea
2
Institute of Quantum Information Processing and Systems,
University of Seoul, 90 Jeonnong,
Tongdaimoon-Ku, 130-743
Seoul, Republic of
Korea
a e-mail: shpark@cu.ac.kr
Received: 2 October 2011
Received in final form: 22 November 2011
Published online: 18 January 2012
Intervalley splittings of pyramidal and cubic Si/SiO2 quantum dot(QD) are investigated using multi-valley effective theory. The cubic QD with a length of 100 Å shows the valley splitting of about 0.21 meV at zero electric field. This value is comparable to 0.18 meV reported for the rectangular Si/SiGe QD with the size of 250 × 200 × 100 Å3. The valley splittings of QD increase with increasing electric field, which can be explained by the increase in the energy difference between symmetric and antisymmetric states. The pyramidal QD shows larger valley splittings than those of the cubic QD with a same size because the cubic QD has larger volume than the pyramidal QD for a given length.
Key words: Mesoscopic and Nanoscale Systems
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag, 2012
