title: Formation of long single quantum dots in high quality InSb nanowires grown by molecular beam epitaxy.
abstract: We report on realization and transport spectroscopy study of single quantum dots (QDs) made from InSb nanowires grown by molecular beam epitaxy (MBE). The nanowires employed are 50-80 nm in diameter and the QDs are defined in the nanowires between the source and drain contacts on a Si/SiO2 substrate. We show that highly tunable QD devices can be realized with the MBE-grown InSb nanowires and the gate-to-dot capacitance extracted in the many-electron regimes is scaled linearly with the longitudinal dot size, demonstrating that the devices are of single InSb nanowire QDs even with a longitudinal size of ∼700 nm. In the few-electron regime, the quantum levels in the QDs are resolved and the Landég-factors extracted for the quantum levels from the magnetotransport measurements are found to be strongly level-dependent and fluctuated in a range of 18-48. A spin-orbit coupling strength is extracted from the magnetic field evolutions of a ground state and its neighboring excited state in an InSb nanowire QD and is on the order of ∼300 μeV. Our results establish that the MBE-grown InSb nanowires are of high crystal quality and are promising for the use in constructing novel quantum devices, such as entangled spin qubits, one-dimensional Wigner crystals and topological quantum computing devices.
authors: Department of Electronics and Key Laboratory for the Physics and Chemistry of Nanodevices, Peking University, Beijing 100871, China. nkang@pku.edu.cn hqxu@pku.edu.cn.
authors: Dingxun
authors: D
authors: Fan
authors: Sen
authors: S
authors: Li
authors: N
authors: N
authors: Kang
authors: Philippe
authors: P
authors: Caroff
authors: L B
authors: LB
authors: Wang
authors: Y Q
authors: YQ
authors: Huang
authors: M T
authors: MT
authors: Deng
authors: C L
authors: CL
authors: Yu
authors: H Q
authors: HQ
authors: Xu