The spin of a single electron is the smallest possible magnetic sensor, operating at the smallest limits of spatial resolution. Research by the quantum technology community in the past couple of decades has opened the capability to control and detect individual electronic spins, in particular the spin associated with the nitrogen-vacancy (NV) point defect in diamond. Integration of NV spins into diamond AFM tips has enabled scanning probe detection of magnetic fields with high sensitivity and spatial resolution of few tens of nanometers (10,000x smaller than the width of a human hair!), over a broad temperature range (from room temperature to the coldest temperatures in the universe - milliKelvin regime). In addition, NV centres in diamond have been used to detect and control individual electronic spins (for example spin-labelled biological proteins on the diamond surface) or even individual nuclear spins of a single atom (13C nuclei in the diamond).

The Quantum Magnetometry Facility at Heriot-Watt University is a 'turn-key' magnetic sensing instrument, based on single NV centres in diamond, operating down to temperatures very close to absolute zero. This facility will enable scientists to prove novel physics in different systems, such as the rich interplay between superconductivity, ferromagnetism and antiferromagnetism in unconventional superconductors, magnetic ordering in atomically-thin 2D materials and heterostructures, etc. These investigations will be very important, for example, to develop new materials and new physical effects that may lead to next-generation "beyond-silicon" electronic devices. Long-term applications of our fundamental investigations could be, for example, Mott transistors, where the gate voltage would switch the device between insulator and metal states, with a much better efficiency than current devices. Or it could provide insights into the enigmatic room temperature superconductor, whose application potential is enormous.