排序方式: 共有42条查询结果,搜索用时 15 毫秒
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Kim J. Matagne P. Leburton J.-P. Martin R.M. Hatano T. Tarucha S. 《Nanotechnology, IEEE Transactions on》2006,5(4):343-349
We use three-dimensional self-consistent Kohn-Sham's equations coupled with Poisson's equation to investigate the electrical behavior of laterally coupled vertical quantum dots (LCVQD) for spin-qubit operation. The shape and the depth of the central gate are changed in different ways to correlate gate geometry with the coupling between the two quantum dots. Upon comparing LCVQD single-gate and the split-gate structures, we found that the two inherently different designs result in different energy barrier profiles leading to dissimilar wavefunction coupling between the two dots. Finally, we show that the doping concentrations in the layered structure could be optimized for practical two-qubit operation. 相似文献
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The transient high-field conductivity of a simple model of polar semiconductors is studied. In this model, it is assumed that the only possible scattering mechanisms is the emission of longitudinal optical (LO) phonons. The time-dependent Boltzmann equation is solved analytically. The behavior of the distribution function is shown for a short period of time after the electric field is applied.Work performed in the framework of the joint project ESIS (electronic structure in solids) of the University of Antwerp and the University of Liège. 相似文献
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We show that a semiconductor membrane made of two thin layers of opposite (n- and p-) doping can perform electrically tunable ion current rectification and filtering in a nanopore. Our model is based on the solution of the 3D Poisson equation for the electrostatic potential in a double-cone nanopore combined with a transport model. It predicts that, for appropriate biasing of the membrane-electrolyte system, transitions from ohmic behavior to sharp rectification with vanishing leakage current are achievable. Furthermore, ion current rectifying and filtering regimes of the nanopore correspond to different charge states in the p-n membrane, which can be tuned with appropriate biasing of the n- and p- layers. 相似文献
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We show that a nanopore in a silicon membrane connected to a voltage source can be used as an electrically tunable ion filter.
By applying a voltage between the heavily doped semiconductor and the electrolyte, it is possible to invert the ion population
inside the nanopore and vary the conductance for both cations and anions in order to achieve selective conduction of ions
even in the presence of significant surface charges in the membrane. Our model based on the solution of the Poisson equation
and linear transport theory indicates that in narrow nanopores substantial gain can be achieved by controlling electrically
the width of the charge double layer. 相似文献
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We show that a semiconductor membrane made of two thin layers of opposite (n- and p-) doping can perform electrically tunable ion current rectification and filtering in a nanopore. Our model is based on the
solution of the 3D Poisson equation for the electrostatic potential in a double-cone nanopore, combined with a transport model.
It predicts that for appropriate biasing of the membrane-electrolyte system, transitions from ohmic behavior to sharp rectification
with vanishing leakage current are achievable. Further more, ion current rectifying and filtering regimes of the nanopore
correspond to different charge states in the p–n membrane which can be tuned with appropriate biasing of the n- and p-layers. 相似文献
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Coupled elliptic quantum dots with different aspect ratios containing up to two electrons are studied using a model confinement potential in the presence of magnetic fields. Single and two-particle Schrodinger equations are solved using numerical exact diagonalization to obtain the exchange energy and chemical potentials. As the ratio between the confinement strengths in directions perpendicular and parallel to the coupling direction of the double dots increases, the exchange energy at zero magnetic field increases, while the magnetic field of the singlet-triplet transition decreases. By investigating the charge stability diagram, we find interdot quantum mechanical coupling increases with the dot aspect ratio, whereas the electrostatic coupling between the two dots remains nearly constant. With increasing interdot detuning, the absolute value of the exchange energy increases superlinearly followed by saturation. This behavior is attributed to the electron density differences between the singlet and triplet states in the asymmetric QD systems 相似文献