Modeling the Electronic Structure of Phosphorus Donor Clusters in Quantum Devices

Modeling the electronic structure of phosphorus donor clusters is essential for understanding and predicting the behavior of quantum devices fabricated using atomic precision advanced manufacturing (APAM) techniques. Scanning Tunneling Microscope (STM) lithography is one such technique for creating nanoelectronic devices by placing activated shallow dopants in silicon with atomic precision. To model these devices, we first use kinetic Monte Carlo parameterized from first principles calculations to predict the geometry of phosphorus donor clusters. From these geometries, we predict device performance by applying multivalley effective mass theory, developing a formalism for using a basis of anisotropic atomic orbitals for the envelope functions. We then compare the predicted electronic structure of these donor clusters to experimentally realized devices, reporting on observables such as charging energy and tunnel coupling.