Switzerland successfully develops a quantum sensor that accurately measures the frequency of electromagnetic waves

[China Instrument Network Instrument Development] Recently, the Swiss Federal University of Technology in Zurich issued a news report that the school's solid-state physics laboratory has successfully developed a quantum sensor that accurately measures the frequency of electromagnetic waves.

The basic material of this quantum sensor is a gemstone with a perfect lattice of carbon atoms. By infiltrating nitrogen atoms into it, nitrogen atoms replace some of the carbon atoms and form "holes" in the crystal lattice near the nitrogen atoms. The formation of the so-called "nitrogen-hole-center", which is a quantum system (qubit) with two energy states, can be controlled by the microwave or laser, and its state is placed in a The combination of two energy states can measure weak electric or magnetic fields.

Since this coherent state has a short duration, it is quickly destroyed by outside interference, so it is difficult to obtain accurate results for one measurement. The research team “times out” the measurement time by repeatedly measuring it, and developed an accurate “clock” to achieve the synchronization of multiple measurement results. The experimental results show that the quantum sensor has a measurement accuracy of one millionth of a Hertz, and the sensitivity is extremely high. The actual measured signal intensity is 170 microtesla, which is equivalent to only one percent of the earth's surface magnetic field strength. The noise ratio reaches 10,000 to 1.

This kind of quantum sensor can be made into nano-scale probes with nuclear magnetic resonance technology for the study of the microstructure of matter, the molecular atomic movement process, and so on.

(Original Title: Quantum Sensors for Successful Measurement of Electromagnetic Wave Frequency in Switzerland)