The National Physical Laboratory [NPL] requirement is for a dilution refrigerator to be used for measurements of superconducting quantum processors and other quantum circuits. The purpose is to complement our existing measurement systems and add measurement capability, in particular for long measurements of e.g., superconducting qubits.
The dilution refrigerator needs to be suitable for RF measurements of complex quantum circuits, meaning it must be equipped with a large number of coaxial input lines, as well as low-loss output lines suitable for use with low-noise amplifiers, isolators and parametric amplifiers. In many cases the system will be used to measure two or more independent samples (in different shielded enclosures) concurrently, and it is important that the system design can accommodate this.
The asset must enable the measurement of high-coherence superconducting qubits/processors based on the following:
1) Base temperature of less than or equal to 10 mK.
2) Mixing chamber plate diameter of at least 275mm
3) Low vibrations
4) Plenty of free space available for custom equipment.
5) We do NOT require a magnet.