Electronic spin based enhancement of magnetometer sensitivity

A method of increasing the sensitivity of a magnetometer comprising:

• providing a magnetometer comprising a solid state diamond lattice, the lattice comprising one or more nitrogen vacancy centers having one or more electronic spins, said electronic spins being configured to undergo a Zeeman shift in energy level in the presence of a magnetic field, the Zeeman shift being proportional to the magnetic field strength,
• disposing the lattice in a magnetic field to be measured,
• applying photons of optical radiation,
• applying a sequence of RF pulses to dynamically decouple the electronic spins from mutual spin-spin interactions and from interactions with the lattice to increase the sensitivity of the magnetometer, and
• detecting output optical radiation from the electronic spins of the diamond lattice, after they have been exposed to the photons of optical radiation and RF pulses, to measure the Zeeman shift from the output optical radiation so as to determine the magnetic field.

A method of detecting a magnetic field, comprising:

• applying optical excitation radiation to a solid state electronic spin system disposed in a magnetic field to be measured that contains a plurality of electronic spins within a solid state diamond lattice, the lattice comprising one or more nitrogen vacancy centers having one or more electronic spins, thereby aligning the electronic spin with the magnetic field;
• applying one or more pulses of RF radiation to the aligned electronic spins so as to induce a precession of the electronic spins about the magnetic field to be sensed, the frequency of the precession being linearly related to the magnetic field by the Zeeman shift of the electronic spin energy levels;
• coherently controlling the electronic spins by applying a decoupling sequence of RF pulses so as to decouple the electronic spins from mutual spin-spin interactions and from interactions with the lattice;
• and
• detecting output optical radiation from the solid state electronic spin system after the electronic spins have been subject to the optical excitation radiation and the RF radiation, to measure the Zeeman shift so as to determine the magnetic field.

A vector magnetometer for detecting a magnetic field that is aligned with one of the crystallographic axes of a solid, the vector magnetometer comprising:

• a macroscopic sample of the solid that includes a diamond crystal lattice the lattice comprising a relatively high density of nitrogen vacancy centers having one or more electronic spins,
• an optical source configured to generate optical excitation radiation that causes the electronic spins to align with the magnetic field when the optical radiation is applied to the electronic spins;
• an RF (radiofrequency) source configured to generate pulses of an RF field that induce a precession of the electronic spins about the magnetic field to be sensed, the frequency of the precession being linearly related to the magnetic field by the Zeeman shift of the electronic spin energy levels;
• and
• a detector configured to detect output optical radiation from the solid state electronic spin system after the optical radiation from the optical source and the RF radiation from the RF source have been transmitted through the electronic spins;
• wherein the RF source is further configured to apply the RF radiation only to electronic spins that are aligned along one or more predetermined crystallographic axes.