ParaWave

The overall objective of this project is to develop a novel and practical broadband microwave amplifier capable of operation at and beyond the fundamental, or standard quantum limit, of sensitivity. Applications of this capability are strongly demanded across wide-ranging areas of fundamental and applied physics and engineering, including quantum information processing, quantum computing (for instance in the readout of qubits), quantum metrology (for instance microwave-photon counting), radio-astronomy, medical imaging, communications and other forms of sensing.

The specific objectives of the project are:

  1. To develop a broadband Josephson traveling wave parametric amplifier (JTWPA) utilizing three-wave mixing, with a power gain of 20 dB and flatness of ±3 dB in a one octave range centred on 5 to 6 GHz. The amplifier should include optimisation of circuit design parameters and physical layout, the preparation of functional samples and optimisation of the fabrication technology. JTWPA circuits will be developed in Nb, Al and Nb-Al hybrid technology according to the intended application. (WP1, WP2)

  2. To analyse the amplifier noise and demonstrate thermal noise-squeezing (up to 5 dB) and quantum-limited performance (noise temperature better than hf/kB ~ 0.3 K), and to clarify the role of device parameters (nonlinearity and dispersion, signal gain, bandwidth and dynamic range) in order to optimise the amplifier operation. (WP1, WP2)

  3. To develop reliable and validated quantum amplifier metrology (components and processes) for the characterisation of the JTWPA device and other cryogenic amplifiers. The envisaged metrology platform will allow the characterisation of devices in terms of their gain, bandwidth and harmonic generation. Standard room temperature microwave sources and thermal noise sources will be used for metrological characterisation.

  4. To improve the sensitivity of the JTWPA device to quantum levels with minimum backaction, through integration with quantum sensors and macroscopic quantum systems. In particular, to combine the JTWPA-based preamplifier with nanoSQUID sensors operating in a dispersive mode and rf-single-electron-transistor (rf-SET) charge detectors optimised for error counting in single electron pumps. Both, the SQUID and the superconducting SET (i.e. Cooper-pair transistor) are examples for macroscopic quantum sensors/systems since their behaviour involves a macroscopically large number of Cooper pairs. Further, to demonstrate frequency multiplexing in these circuits, and flux and charge sensitivities approaching the standard quantum limit. (WP4)

  5. To facilitate the take-up of the technology and measurement infrastructure developed in the project by the measurement supply chain (quantum technology professionals) and end users (electronics, healthcare, information and communications industries) including demonstration of the application of the JTWPA device in at least two quantum measurement case studies. (WP4, WP5)