Image: ARC Centre of Excellence for Engineered Quantum Systems logo
Original Published Date: 
Tuesday, December 19, 2017

A University of Sydney team from the Australia Research Council (ARC) Centre of Excellence for Engineered Quantum Systems (EQuS) has solved a common problem in quantum sensing devices, which are used in biomedical imaging and have defence applications.

Industrial sensors are everywhere in our technology and in order to function successfully they must be able to identify tiny signals from a cluttered background.

For most humans this is simple. Walk into a crowded room and you can pick out a single voice while ignoring everyone else. That trick isn’t so easy for industrial sensors—and the challenge gets even harder for super-sensitive quantum devices.

Now, a team led by Professor Michael J. Biercuk from the University of Sydney, in collaboration with Dartmouth College and Johns Hopkins Applied Physics Laboratory in the US, has developed quantum control techniques enabling a new generation of ultra-sensitive sensors that can identify tiny signals while rejecting background noise down to theoretical limits.

“By applying the right quantum controls to a qubit-based sensor, we can adjust its response in a way that guarantees the best possible exclusion of the background clutter – that is, the other voices in the room,” said Professor Biercuk, a chief investigator at EQuS.

While devices themselves have improved, the measurement protocols used to capture and interpret the signals have lagged behind. Quantum sensors therefore often return fuzzy results, which complicates interpretation of the data through a phenomenon known as “spectral leakage”—a bit like being distracted by the wrong voices in the room.

The University of Sydney research, published on Tuesday in Nature Communications, demonstrates control protocols that will help take advantage of improved sensor hardware.

Media issued by EQUS.

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Image: ARC Centre of Excellence for Engineered Quantum Systems logo 
Credit: ARC Centre of Excellence for Engineered Quantum Systems