New quantum circuit lets researchers listen to weakest radio signals

Researchers from Delft University of Technology have created a new quantum circuit that allows them to listen to the weakest radio signals that are allowed by quantum mechanics. The team sees the circuit with potential uses in future applications like radio astronomy and medical imaging using MRI tech. The chip also will enable researchers to perform experiments that could yield new information on the interplay of quantum mechanics and gravity.

Specifically, the chip allows researchers to demonstrate the detection of photons or quanta of energy, which are the weakest signals allowed by the theory of quantum mechanics. Professor Gary Steele describes a quanta as a tiny little chunk of energy.

Quanta's are one of the strange predictions in quantum mechanics. Researcher Mario Gely describes quanta, "Say I am pushing a kid on a swing. In the classical theory of physics, if I want the kid to go a little bit faster I can give them a small push, giving them more speed and more energy. Quantum mechanics says something different: I can only increase the kid's energy one 'quantum step' at a time. Pushing by half of that amount is not possible."

In that scenario, the quantum steps in pushing a kid on the swing are too small to notice. The same is no longer true about radio signals. The researchers developed a circuit that can detect quanta in radio frequency signals.

One key goal for the team is to describe the interaction between gravity and quantum mechanics. The team wants to listen and control the quantum vibrations of heavy objects and explore what happens when quantum mechanics and gravity are mixed.