Magnetic Shifts of Coulomb Peaks in Strongly Coupled Quantum Dot Array in Silicon

Atomically precise donor-based quantum devices in silicon are fabricated using STM lithography, which has become a promising platform for solid state quantum computation and analog quantum simulation. Recently, we have been made arrayed quantum dot devices with varying array constants to include coupling regimes from weak to strong. As the array constants become smaller, the individual dots no longer act as discrete sites with localized electrons in the Fermi-Hubbard model and instead behave as a single, large coherent quantum construct with complex internal structure and electrons occupying many body eigenstates across the array. I will discuss the behavior of arrayed quantum dots in the strongly coupled regime where the electrons delocalize across the ordered 3x3 dot arrays. We describe quantum transport measurements through the arrays. We apply an external magnetic field to explore the effects on charge/spin configurations inside the arrays. The positions of the Coulomb peaks shift in complex ways revealing the subtle dependence of the array energy spectrum on an external B field. We quantify the magnetic field induced shifts in the electron addition spectrum of our quantum dot arrays and analyze the addition spectrum using a generalized Fermi-Hubbard model from the strong to weak coupling regime.