Engineering Majorana bound states in coupled quantum dots in a two-dimensional electron gas

Majorana bound states (MBSs) can emerge in superconductor-semiconductor hybrids, by engineering artificial Kitaev chains. In this work, we realize a two-site Kitaev chain in a two-dimensional electron gas (2DEG) by coupling two quantum dots (QDs) through a region proximitized by a superconductor. We demonstrate systematic control over inter-dot couplings through in-plane rotations of the magnetic field and via electrostatic gating of the proximitized region.This allows us to tune the system to sweet spots in parameter space, where robust correlated zero bias conductance peaks are observed in tunnelling spectroscopy. By studying the evolution of the energy spectrum with magnetic field, we show that it is possible to experimentally distinguish between high and low Majorana polarization regimes, an important metric for Majorana-based qubits. The presented implementation of a Kitaev chain on a scalable and flexible 2D platform provides a realistic path towards more advanced experiments that require manipulation and readout of multiple MBSs.