Electrostatic Formation and Charge Stability of Gate-Defined Double Quantum Dots in Silicon MOS Structures

In this work, we investigate how an array of isolated gate electrodes influences the formation and electrostatic behavior of double quantum dots (DQDs) at the silicon/silicon dioxide interface in a metal–oxide–semiconductor (MOS) structure. We propose a modeling approach that predicts the formation of two coupled quantum dots by applying a combination of positive and negative voltages to the gates. Using a two-dimensional self-consistent solution of the Poisson and Schr¨odinger equations, we compute the surface potential and charge distribution, obtaining results consistent with those in [1]. We further examine the effect of gate voltage variations on the charge stability diagram, demonstrating the sensitivity of dot size and charge density to small voltage changes. The capacitance matrix is extracted, and the resulting electrostatic energy calculations provide insights into the system’s charge transport behavior, as reflected in the charge stability diagram. Our findings highlight the strong sensitivity of silicon-based spin qubits to gate voltages and reinforce the suitability of silicon MOS platforms for quantum computing applications, owing to their compatibility with standard CMOS fabrication technologies.