Interplay of exchange and superexchange in triple quantum dots

Recent experiments on semiconductor quantum dots have demonstrated the ability to utilize a large quantum dot to mediate superexchange interactions and generate entanglement between distant spins. This opens up a possible mechanism for selectively coupling pairs of remote spins in a larger network of quantum dots. We will describe our theoretical efforts to understand the controllability of superexchange interactions in these systems. We focus on a triple-dot system arranged in a triangular configuration and use configuration interaction calculations to investigate the interplay of superexchange and nearest-neighbor exchange interactions as the geometry and detuning of the mediating dot are varied. We also study how the strength and sign of the superexchange coupling depends on the number of electrons in the mediator. Our results can be used as a guide to assist further experimental efforts towards scaling up to larger, two-dimensional quantum dot arrays.