wigner molecule formation and their effect on silicon mos qubit perfomance

Silicon MOS quantum dots are emerging as a promising platform for scalable spin qubits. One of the bedrocks of this progress is the need for robust and reliable two qubit gates, however as we search for alternative configurations to the (1,1) regime, we find that gate parameters and voltage space become increasingly difficult to navigate. 

As we explore devices in the multi-electron regime, strong Coulomb interactions become a dominant, driving the system from a delocalised Fermi liquid into a wigner molecule state, where electrons become spatially localised, where the many-body correlation-driven phenomenon fundamentally alters the device's energy spectrum and electronic structure.

In this work  we examine gate parameters and explore the formation of wigner molecules in few-electron Si-MOS quantum dots, based primarily on numerical simulation techniques such as the full configuration interaction. 

Our focus is to quantify the potential impact of Wigner molecularisation and we demonstrate the effect on the orbital and valley degrees of freedom and the effect on the exchange interaction, and therefore gate design for the ideal two qubit gate.