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Spinning diamonds for quantum precision

Spinning diamonds for quantum precision

 If the diamond rotates in the same direction (orange) as the carbon-13, the quantum sensor sees a slower spin (and lower pseudo magnetic field), while if the diamond rotates in the opposite direction (purple) the quantum sensor sees a faster spin (and la

A group of physicists at The University of Melbourne have found a way to reduce the noise experienced by quantum sensors just by spinning them.

Quantum sensors are highly sensitive, and among their many promising applications, they are ushering in a new era of MRI (Magnetic Resonance Imaging) that is making visible the tiny details inside cells and proteins—but external magnetic fields can easily break their crucial quantum state. By introducing extra spin, the researchers have discovered they can ‘trick’ a quantum system to keep it going.

A particularly promising quantum sensor is the nitrogen vacancy (NV) centre, found in diamonds. Quantum states rely on a property called coherence, which is sensitive to environmental ‘noise’ that can lead to a loss of the quantum state, known as ‘dephasing’. Study leader, Associate Professor Andy Martin, said that maintaining the quantum state of NV centres is hard. “A quantum state is fragile. It’s fragile to the magnetic field in particular. If you have fluctuations in the magnetic field it will dephase the quantum sensor,” said Associate Professor Martin. “Maintaining the quantum state is the key to using NV systems as quantum sensors of nano-scale environments.”

In the study, which was supported by an ARC Discovery Project grant, they sought to reduce the effect of dephasing by rotating the whole system at high speed. While this technique could soon be used to improve the precision of quantum MRI scanners, Associate Professor Martin says it may also help to answer some fundamental questions in physics.

 

Media issued by The University of Melbourne.

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