Device package

One of the central elements of the device package is the Device class, which can model a wide range of real-world devices. In the first tutorial of this section, a nanowire quantum dot is implemented as a QTCAD Device object; the Schrödinger and Poisson equations are then solved successsively in this system over a static mesh. In the second tutorial, we explain how to use adaptive meshing for more robust solutions of the non-linear Poisson equation at cryogenic temperature. In the third tutorial, we explain how to account for user-defined parasistic background volume and surface charge densities when solving the non-linear Poisson equation. In the fourth tutorial, the Schrödinger equation is solved in a specific region of a device after solving the non-linear Poisson equation with an adaptive mesh. In the fifth tutorial, the Schrödinger equation is solved in a quantum dot. In the sixth tutorial, the alignment of bands in heterostructures is explained. In the seventh tutorial, the output of QTCAD simulations (e.g. electric potential and wavefunctions) are visualized in ParaView. In the eighth tutorial, the Schrödinger and Poisson equations are solved self-consistently for a 1D metal–oxide–semiconductor capacitor. In the ninth tutorial, we get the band structure for holes confined to a 1D particle-in-a-box-like quantum well. In the tenth tutorial, we look at the effects of spin–orbit coupling for holes subject to a constant magnetic field. In the eleventh tutorial, we demonstrate how strain can be used to modify the character of the ground-state hole wavefunction. In the twelfth tutorial, the eigenstates of an electron confined to a silicon quantum well are found using a 1D multi-valley effective-mass theory and the valley splitting is analyzed as a function of an applied electric field. In the thirteenth tutorial, the eigenstates of an electron bound to a phosphorus donor in silicon are found using a 3D multi-valley effective-mass theory and a central-cell correction. In the fourteenth tutorial, the many-body problem is solved for the nanowire quantum dot studied in the first tutorial. In the fifteenth tutorial, a function is defined to produce Device objects for double quantum dots defined in a generic fully-depleted silicon-on-insulator (FD-SOI) geometry. We study tunnel coupling in such double-dot FD-SOI devices in tutorials sixteen and seventeen of this section and exchange coupling in tutorials eighteen and nineteen. Finally, in tutorial twenty, we investigate how point charges can affect the quantum-dot energy spectrum in this same FD-SOI setting.

• 1. Poisson and Schrödinger simulation of a nanowire quantum dot
• 2. Poisson solver with adaptive meshing
• 3. Poisson solver with background charges
• 4. Adaptive-mesh Poisson solver combined with the Schrödinger solver
• 5. Schrödinger equation for a quantum dot
• 6. Band alignment in heterostructures
• 7. Visualizing QTCAD quantities with ParaView
• 8. Self-consistent Schrödinger–Poisson simulation of a MOS capacitor
• 9. Schrödinger simulation of a quantum well
• 10. Including spin–orbit coupling and magnetic effects in a simulation
• 11. Including strain in a simulation
• 12. Valley splitting (MVEMT)
• 13. MVEMT applied to a donor in silicon
• 14. Many-body analysis of a nanowire quantum dot
• 15. A double quantum dot device in a fully-depleted silicon-on-insulator transistor
• 16. Tunnel coupling in a double quantum dot in FD-SOI—Part 1: Plunger gate tuning
• 17. Tunnel coupling in a double quantum dot in FD-SOI—Part 2: Tuning the barrier gate
• 18. Exchange coupling in a double quantum dot in FD-SOI—Part 1: Perturbation theory
• 19. Exchange coupling in a double quantum dot in FD-SOI—Part 2: Exact diagonalization
• 20. Point charges in a double quantum dot in FD-SOI