title: Towards controllable growth of self-assembled SiGe single and double quantum dot nanostructures.
abstract: Fabrication of semiconductor single and double quantum dot (QD) nanostructures is of utmost importance due to their promising applications in the study of advanced cavity quantum electrodynamics, quantum optics and solid-state spin qubits. We present results about the controllable growth of self-assembled single and double SiGe QD arrays with an ultra-low areal density of 1 × 10(7) cm(-2) on nanohole-patterned Si substrates via molecular beam epitaxy. The two dots in a double QD (DQD) aligned along the elongation direction of the nanoholes and show unsymmetrical features in both size and composition due to the asymmetric nanohole profiles after Si buffer layer growth. The interdot spacing between the two dots in a DQD could well be adjusted by changing the elongation ratio of nanoholes. Moreover, whether a single or a double QD formed in a given nanohole was found to be determined by the growth temperature of the Si buffer layer, the reason of which is given by the calculation of the surface chemical potential around the nanoholes after the buffer layer growth.
authors.affiliation: State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education) and Department of Physics, Fudan University, Shanghai 200433, China. zmjiang@fudan.edu.cn.
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Ma
authors.forename: Shufan
authors.initials: S
authors.lastname: Huang
authors.forename: Cheng
authors.initials: C
authors.lastname: Zeng
authors.forename: Tianyuan
authors.initials: T
authors.lastname: Zhou
authors.forename: Zhenyang
authors.initials: Z
authors.lastname: Zhong
authors.forename: Tong
authors.initials: T
authors.lastname: Zhou
authors.forename: Yongliang
authors.initials: Y
authors.lastname: Fan
authors.forename: Xinju
authors.initials: X
authors.lastname: Yang
authors.forename: Jinsong
authors.initials: J
authors.lastname: Xia
authors.forename: Zuimin
authors.initials: Z
authors.lastname: Jiang
mesh_terms: D005857:Germanium / Q000737:chemistry*; D045663:Quantum Dots / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*
chemical_list: D005857:Germanium; D012825:Silicon