Details

Autor(en) / Beteiligte

• Zinovyev, V A
• Dvurechenskii, A V
• Kuchinskaya, P A
• Armbrister, V A

Titel

Strain-induced formation of fourfold symmetric SiGe quantum dot molecules

Ist Teil von

• Physical review letters, 2013-12, Vol.111 (26), p.265501-265501, Article 265501

Ort / Verlag

United States

Erscheinungsjahr

2013

Quelle

American Physical Society Journals

Beschreibungen/Notizen

• The strain field distribution at the surface of a multilayer structure with disklike SiGe nanomounds formed by heteroepitaxy is exploited to arrange the symmetric quantum dot molecules typically consisting of four elongated quantum dots ordered along the [010] and [100] directions. The morphological transition from fourfold quantum dot molecules to continuous fortresslike quantum rings with an increasing amount of deposited Ge is revealed. We examine key mechanisms underlying the formation of lateral quantum dot molecules by using scanning tunneling microscopy and numerical calculations of the strain energy distribution on the top of disklike SiGe nanomounds. Experimental data are well described by a simple thermodynamic model based on the accurate evaluation of the strain dependent part of the surface chemical potential. The spatial arrangement of quantum dots inside molecules is attributed to the effect of elastic property anisotropy.