Parametric amplification with quantum dots

At present the sensitivity of spin qubit measurements is not limited by any fundamental physics but, typically, by the noise floor of the first-stage amplifier. In the superconducting qubit community the Josephson Parametric Amplifier (JPA) has been developed to enable fast qubit readout, which has demonstrated quantum-limited noise performance. But the JPA is highly sensitive to magnetic fields and is not ideal for integration with spin qubit experiments. An alternative possibility is to implement a parametric amplifier by taking advantage of the nonlinear capacitance of a quantum dot. I will discuss this nonlinear behavior and how it applies to the requirements for parametric amplification. Theoretical analysis shows the quantum dot parametric amplifier is feasible and a demonstration experiment is currently in development.