Microscopic Model of the Electron-on-Neon Qubit

Electrons trapped on solid neon surfaces exhibit remarkably long coherence times, making them a promising platform for quantum computation. However, the microscopic origin of the charge states remains a mystery. In this work, we present a microscopic model of the electron-on-neon (eNe) qubit based on the interaction between a floating electron on the neon surface and charge defects at the Si/SiOx interface. Using realistic material parameters, our model reproduces the experimentally observed voltage dependence of the qubit transition frequency and electric dipole moment. We provide further experimental evidence supporting this model by characterizing eNe charge states formed on smooth Si surfaces prepared with different passivation treatments.