We have observed strong photoluminescence from a single CdSe quantum dot embedded in a ZnSe nanowire. Exciton, biexciton and charged exciton lines have been identified unambiguously using photon correlation spectroscopy. This technique has provided a detailed picture of the dynamics of this new system. This type of semi conducting quantum dot turns out to be a very efficient single photon source in the visible. Its particular growth technique opens new possibilities as compared to the usual self-asssembled quantum dots.
Emission of Linearly Polarized Single Photons from Quantum Dots Contained in Nonpolar, Semipolar, and Polar Sections of Pencil-Like InGaN/GaN Nanowires
Quantum dots acting as single photon emitters in the blue-green range are fabricated and characterized at cryogenic temperature. They consist in CdSe dots inserted in (Zn,Mg)Se nanowires with a thick shell. Photoluminescence spectra, decay curves and autocorrelation functions were measured under nonresonant continuous-wave and pulsed excitation. An analytical approach is applied simultaneously to the decay curves and correlation functions. It allows a quantitative description of how these two quantities are affected by the exciton rise due to biexciton feeding, the bright exciton decay, the ef…
We report shot noise measurements for a quantum dot formed in an InAs nanowire suspended between superconducting electrodes. We find a clear alternation for the shot noise value in the Coulomb blockade regime between even and odd electron occupation in the dot, indicating that super-Poissonian (Poissonian) shot noise with the Fano factor reaching around 2 (1) occurs for even (odd) parity. With increasing magnetic field, the parity effect disappears and all the regimes show the Fano factor of around 1. The whole observation in our experiments quantitatively agrees with simulation obtained from …
On controlling the bound states in quantum-dot hybrid-nanowire
最近的实验使用量子点耦合到拓扑超导纳米线[M. T. Deng等人，科学354，1557（2016）}]揭示了零能量束缚态从Andreev束缚态聚结。这种存在于量子点中的准粒子态可以通过磁和静电手段来控制。我们使用量子点-纳米线结构的微观模型来再现实验结果，应用Bogoliubov-de ~Gennes技术。这是通过研究各种类型的束缚态的栅极电压依赖性和它们之间的相互影响来完成的。我们证明了零能束缚态可以从Andreev束缚态中以拓扑平凡的相位出现，并且可以通过各种手段进行控制。在非平凡拓扑相中，我们证明了这个零能级与Majorana束缚态之间可能的共振。我们讨论并解释了这种现象的结果所讨论的束缚态的主导自旋字符。所提出的结果可以应用在实验研究中，通过使用所提出的纳米器件。
The influence of pre-strain and temperature on the superior properties exhibited by an Nb nanowire embedded in a NiTi shape memory alloy (SMA) are investigated via molecular dynamics simulations. To this end, a new Nb-Ni-Ti ternary interatomic potential based on the second nearest-neighbor modified embedded-atom method (2NN MEAM) is developed and employed. The origin of the unique phenomena of quasi-linear elasticity, slim hysteresis, and reduction in Young's modulus observed for pre-strained nanowire-SMA composites is uncovered. The results demonstrate the importance of plastic deformation in…
