Sensing dot with high output swing for scalable baseband readout of spin qubits

Understand

A crucial requirement for quantum computing, in particular for scalable quantum computing and error correction, is a fast and high-fidelity qubit readout.

• For semiconductor based qubits, one limiting factor for local low-power signal amplification, is the output swing of the charge sensor.
• We demonstrate GaAs and Si/SiGe asymmetric sensing dots (ASDs) specifically designed to provide a significantly improved response compared to conventional charge sensing dots.
• Our ASD design features a strongly decoupled drain reservoir from the sensor dot, which mitigates negative feedback effects found in conventional sensors.