Projects

qdot-tools

This is a collection of nanostructure simulation and modeling programs for self assembled quantum dots and other nanostructures. Atomic Nanostructure Layout Code: geomThis program, geom, is a simple utility for turning nanostructure descriptions into atomic layout. These atomic positions are ... [More] common input for several types of quantum dot models, such as tight-binding or empirical pseudopotentials. The user specifies the size, shape, and composition of a coherent III-V or group IV semiconductor heterostructure. Shapes include lens, pyramidal, and conical dots, as well as quantum wells, and may be filled with different alloy or pure materials. Output is an HDF5 file, struct.h5, containing atom positions, chemical identities, lattice indexing, and neighbor tables. The object-oriented design makes it easy for users to add new shapes and materials to this utility. Libraries used: HDF5, libxml2 Strain Relaxation Code: relaxThis program, relax, uses a conjugate-gradient algorithm to relax atomic positions in coherently strained semiconductor nanostructures. A typical simulation of millions of atoms in and around an embeded quantum dot runs in a few hours on a typical PC. Input is an HDF5 file, struct.h5, containing the atomic positions, identities, and neighbor tables. The program output, relaxed.h5, is the relaxed atomic positions in the same HDF5 format as the input file, suitable for input into an atomistic electronic structure model. Also calculates stress for each atom. Libraries used: HDF5, libxml2, blitz Effective Mass Model Generator: getemaThis program, getema, extracts an effective mass model boffset.h5 from a relaxed nanostructure relaxed,h5. The strained band offsets in boffset.h5 can be used as input to our pi path integral quantum Monte Carlo code. Libraries used: HDF5, libxml2, blitz [Less]