NEMO - 3D
NEMO 3-D calculates eigenstates in (almost) arbitrarily shaped semiconductor structures in the typical column IV and III-V materials. Atoms are represented by the empirical tight binding model using s, sp3s*, or sp3d5s* models with or without spin. Strain is computed using the classical alence force field (VFF) with various Keating-like potentials.
The development of the simulator is summarized in a 2002 invited publication in Computer Modeling in Engineering and Science [J36], and in a 2007 Special Issue on Nanoelectronic Modeling in IEEE Transectaion on Electron Devices (Part I - Models and Benchmarks [J85], Part II - Applications [J86]).
NEMO3D has been used to analyze quantum dots [P47, P53], alloyed quantum dots [J36,J42, P34, P35,P38], long range strain effects on quantum dots [J42,J44,J69, P38, P59, P62, P76], effects of wetting layers [J52, P46], piezo-electric effects in quantum dots [J86, P76,P80], quantum dot nuclear spin interactions [J55, P43, P47], quantum dot phonon spectra [J53, P45, P48], coupled quantum dot systems [J53,J69, P75], miscut Si quantum wells with SiGe alloy buffers [J79], core-shell nanowires [J81], alloyed nanowires [J71,J77,J86, P77], phosphorous impurities in Silicon (P:Si qbits) [J89], bulk alloys [J75,J88]. Boundary conditions to treat the effects of (surface states have been developed [J49, P41]. Direct and exchange interactions [P53] and interactions with electromagnetic fields [J35] can be computed in a post-processing approach based on the NEMO 3-D single particle states.
Some high-level overview on the following NEMO 3-D research results are available:
- Fine Structure Splitting in QDs Crystal Symmetry, Strain, and Piezo-Electricity. The work is published in [J104, P76]
- Spectral energy tuning of InAs quantum dots with InGaAs quantum wells. The work is accepted for publication.
- High precision quantum control of single donor spins in Si. published in PRL [J89]
- Gate induced quantum confinement transition of a single dopant atom in a Si FinFET, published in Nature Physics [J102].
- Transport-based dopant mapping in advanced FinFETs, published at IEDM 2008 [P105].
- Anisotropic Hyperfine Interaction (AHF)
- Coherent Transport Adiabatic Passage (CTAP)
- D- Modeling for As Donors
- Charge Qubit Control
Techniques to visualize 21 million atoms on a single GPU were developed [P64] and migrated into a unique visualization system that can serve hundreds of simultaneous users [J73] on the nanoHUB. Supported by the nanoHUB infrastructure the NEMO3D team is dedicated to move research applications [P61] out of the hands of experts and bridge research and education [P74]. The "Quantum Dot Lab" on nanoHUB is powered by NEMO 3-D.
NEMO 3-D has been parallelized using MPI, been ported to many platforms [P57,P82] and recently been benchmarked to efficiently use 8,192 processors.
NEMO 3-D is available as open source and also accessible in the nanoHUB as the "Quantum Dot Lab".