Technology computer-aided design simulations of spin qubits in gated double quantum dots

The design and engineering of classical silicon-based microelectronics often relies on a mature set of computational tools. Among these tools are technology computer-aided design (TCAD) software which are used to predict device performance and trends before fabrication. As we move toward using silicon for quantum technologies in the form of, e.g., spin qubits, it seems plausible that we will need to adopt best practices employed for classical semiconductor systems. However, because of the fundamental differences in operating principles between classical and quantum hardware, specialized quantum TCAD tools must be developed for quantum systems. In this work, we use the spin-qubit device modeling software package QTCAD to perform TCAD simulations of double-dot devices. In particular, we compute charge-stability diagrams, tunneling rates, and exchange energies in specific electron and hole silicon double-dot devices (e.g., FD-SOI devices) and predict how these properties can be modified by changing experimental configurations, starting only from device layouts and design rules. We identify schemes (e.g., based on the lever-arm and Hubbard approximations) which present sufficient accuracy while keeping computation times compatible with the rapid simulation requirements of the semiconductor industry.