National Physical Laboratory

Cryogenic Signal Processing Cryogenic Signal Processing

NPL is developing superconducting devices and associated measurement systems for signal processing at cryogenic temperatures.

Our research area is directed at the development of devices and circuits for detection and amplification of electrical signals at cryogenic temperatures. Devices based on superconducting elements offer the potential to measure at the quantum limit whereas existing circuits, based on semiconductor devices, typically have a noise level at least an order of magnitude higher than this. In addition, superconducting devices can make quantum accurate measurements in terms of the flux quantum, h/2e.

Nanobridge readout of single photon detectors: Superconducting nanobridge devices can be used to process the signal from superconducting nanowire single photon detector arrays. We are developing this technology as part of an Innovate UK funded feasibility study, with the University of Glasgow and the London Centre for Nanotechnology.

Quantum Voltage Synthesizer: Arrays of Josephson junctions can be used to generate voltages at practical laboratory levels. NPL has developed a quantum voltage synthesizer for generation of waveforms directly in terms of the Josephson effect.

High Bandwidth Quantum Voltage Digitiser: Delta-sigma modulation techniques can be used in combination with a Josephson junction to provide a quantum-accurate digitizer. NPL is developing this technology in collaboration with European partners.

Superconducting Nanobridges: Josephson junctions can be created using nanoscale weak links fabricated out of thin superconducting films. A first application we are studying is a Josephson comparator.

Mechanically-cooled Cryogenic Current Comparator: Cryogenic current comparators are a key technology in electrical metrology. We are developing a version which will not rely on a supply of liquid helium.

People working on the project

External collaborators


Please note that the information will not be divulged to third parties, or used without your permission