Jonas Lima

The spin of electrons is a natural two-level system that works as an excellent qubit. The control of the spin of isolated electrons in silicon-based heterostructures is very promising for high performance and scalable qubits. To achieve this, it is very important to predict and control the valley splitting in this system, since a very fast qubit relaxation is obtained, for instance, when the valley splitting becomes equal to the qubit Zeeman splitting. For this reason, different works have investigated the valley splitting in silicon spin qubits, both experimentally and theoretically. In this work we used the effective mass theory, which enables us to obtain the electron envelope function, to predict the valley splitting of silicon-based heterostructures, where we consider smooth interfaces in the heterostructure. We obtain how the valley splitting can be tuned by the width of the interfaces and compare our results with results obtained by other methods.