Interface optimization for low noise GaAs based heterostructures for qubit and energy applications

Project description:

It has recently become clear that charge noise in current host structures severely limits the scalability of semiconductor qubits. Within this project, ultra-low-noise GaAs-based semiconductor heterostructures incorporating systematic noise reducing measures will be developed using state-of-the-art epitaxial and deposition techniques. The aim of the project is to characterize, understand and reduce material and especially interface related charge noise via different routes. To eliminate the noise due to dopants, undoped gate-induced heterostructures will be explored. The effects from surface and interface defects will be minimized by testing epitaxial doped semiconductor gates and in-situ deposited or epitaxial gate stacks. Noise characterization with transport measurements through quantum point contacts (QPCs) will be carried out within this project to ensure short feedback loops. Charge-noise related dephasing of qubits fabricated from the most promising heterostructures will be measured. In addition to the optimisation of the heterostructures for electrostatic qubit projects, low noise heterostructures with optically active self-assembled quantum dots (QDs) will be tailored to be used for developing optical interface capabilities for gated QD qubits and energy harvesters such as solar cells or thermoelectric power generators.

Project leader: Arne Ludwig
Doktorandenprogramm der IMPRS-SurMat