Sadre Momtaz Zahra, Servino Stefano, Demontis Valeria, Zannier Valentina, Ercolani Daniele, Rossi Francesca, Rossella Francesco, Sorba Lucia, Beltram Fabio, Roddaro Stefano
NEST, Instituto Nanoscienze CNR and Scuola Normale Superiore, Piazza S. Silvestro 12, I-56127 Pisa, Italy.
Department of Physics "E.Fermi", Università di Pisa, Largo Pontecorvo 3, I-56127 Pisa, Italy.
Nano Lett. 2020 Mar 11;20(3):1693-1699. doi: 10.1021/acs.nanolett.9b04850. Epub 2020 Feb 18.
We report results on the control of barrier transparency in InAs/InP nanowire quantum dots via the electrostatic control of the device electron states. Recent works demonstrated that barrier transparency in this class of devices displays a general trend just depending on the total orbital energy of the trapped electrons. We show that a qualitatively different regime is observed at relatively low filling numbers, where tunneling rates are rather controlled by the axial configuration of the electron orbital. Transmission rates versus filling are further modified by acting on the radial configuration of the orbitals by means of electrostatic gating, and the barrier transparency for the various orbitals is found to evolve as expected from numerical simulations. The possibility to exploit this mechanism to achieve a controlled continuous tuning of the tunneling rate of an individual Coulomb blockade resonance is discussed.
我们报告了通过对器件电子态进行静电控制来调控InAs/InP纳米线量子点中势垒透明度的结果。近期研究表明，这类器件中的势垒透明度呈现出仅依赖于被俘获电子的总轨道能量的一般趋势。我们表明，在相对较低的填充数下会观察到一种性质不同的情况，此时隧穿速率相当程度上由电子轨道的轴向构型控制。通过静电门控作用于轨道的径向构型，传输速率与填充数的关系会进一步改变，并且发现各个轨道的势垒透明度如数值模拟所预期的那样演变。文中还讨论了利用这种机制实现对单个库仑阻塞共振隧穿速率进行可控连续调谐的可能性。
