3D modeling of silicon quantum dots

Transport in split-gate silicon quantum dots

“…The determination of the exact behavior of the dot states with bias requires fully self-consistent analysis of the eigenstates in this three-dimensional structure. Such studies are presently underway, and indicate that such symmetry breaking by the applied bias may account for crossing behavior when asymmetric bias is applied [8], although less so for the present case in which all the gates are tied together, suggestive that multi-particle effects still play an important role in determining the exact spectrum of states in the dot.…”

3D modeling of discrete impurity effects in silicon quantum dots: energy level spacing and scarring effects

“…We also investigated the influence of discrete dopant atoms on the agreement between conductance peaks derived theoretically and those measured experimentally. For the case of a continuum doping model, the results of a similar comparison were reported previously [3]. Here, we examine how treating the impurities discretely affects the calculated conductance peaks.…”

“…Figure 3A shows the experimentally measured conductance peaks at liquid helium temperature, while Fig. 3B shows the results derived by implementing the method described in [3,4] and using the discrete impurity model to describe the charge in the substrate. As shown by these figures, we are able to reproduce the slope of the experimental result in our theoretical model.…”

“…Details about the implementation of the 3D Schrödinger-Poisson equation solver used in these investigations can be found in Refs [3,4]. In Section 2, we describe the procedure used for generating the discrete † E-mail: srdjndsuFedu ‡ E-mail: rihrdFkisdsuFedu impurity distribution in the dot active region.…”

QCAD Simulation and Optimization of Semiconductor Quantum Dots

“…It was also essential that such a tool be able to simulate and optimize many different single-and multi-QD structures very efficiently, and provide fast feedback on which device layouts are more likely to lead to few-electron behavior. Although there have been numerous papers [9][10][11][12][13] on simulation methods for quantum dots, they focus on different issues than those addressed in this work. Existing commercial 14 and academic 15 device simulators either target roomtemperature and many-electron devices, whereas qubit applications require temperatures close to zero Kelvin and one/few-electron devices, or target simple and few geometries, whereas multi-QD devices have very complex three-dimensional (3D) shapes and can have many different layouts due to their inherently large design a) xngao@sandia.gov space.…”