University of Jyväskylä

New frontiers of quantum mechanics

Researchers have demonstrated how some of the most counterintuitive predictions of quantum mechanics can be verified in nearly-macroscopic objects. This provides new tools for the technological applications especially a widespread intrinsically secure communication.

Quantum mechanics is difficult to understand. It is usually considered as a theory that describes the world of the infinitesimally small: a world of subatomic particles behaving in bizarre ways, far removed from the phenomena we are familiar with in our daily life. One example is provided by entanglement: the dynamics of two quantum particles can be prepared such that their motion is inextricably correlated, in ways that would be impossible for objects described by classical physics. One consequence of entanglement is what Einstein defined "spooky action at a distance": entangled particles cannot be described independently even though they might lie light-years away from each other. In recent years, researchers have been exploring, both from the theoretical and the experimental point of view, how these bizarre laws can be applied to larger systems, at scales closer to our everyday experience.

Novel tools for the technological applications

Now researchers at the University of Jyväskylä (Finland) participated in an international collaboration with research groups from Aalto University (Finland), UNSW (Australia) and University of Chicago (United States) and showed that it is possible to create an entangled state for the dynamics of two mechanical objects each constituted by 1012 (1 followed by twelve zeroes) atoms! This allowed them to demonstrate how some of the most counterintuitive predictions of quantum mechanics can be verified in nearly-macroscopic objects.

We achieved this result by placing two vibrating membranes –the mechanical objects– in a microwave circuit. It was shown that, by shining the right combination of microwave electromagnetic fields to this circuit, the two vibrating membranes enter a quantum-correlated state of motion, impossible for classical objects.” tells postdoctoral researcher Asjad Muhammad from Department of Physics at the University of Jyväskylä.

Our result not only provides new insights into the quantum behavior of macroscopic objects, but, potentially, can also be turned into technological applications, for instance, in the field of ultra-sensitive measurements or intrinsically secure communications.” says researcher group leader Academy Research Fellow Francesco Massel from Department of Physics at the University of Jyväskylä.

Additional information:

silicon chips
An illustration of the 15-micrometre-wide drumheads prepared on<br /> silicon chips used in the experiment. Image: Aalto University / Petja<br /> Hyttinen &amp; Olli Hanhirova, ARKH Architects.
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