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.

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

Quantum mechanics that is difficult to understand, usually considered as a hypothesis describing the world of the infinitesimally small particles. They are far removed from the phenomena of our daily life. One example of it includes quantum entanglement, a physical phenomenon which occurs when pairs or groups of particles are generated or interact in ways such that the quantum state of each particle cannot be described independently of the state of the other.

One consequence of entanglement is the thing that Einstein characterized “spooky action at a distance”: entangled particles can’t be depicted autonomously despite the fact that they may lie light-years from each other. In recent years, specialists have been investigating, both from the hypothetical and the trial perspective, how these odd laws can be connected to bigger frameworks, at scales nearer to our ordinary experience.

Now researchers at the University of Jyväskylä (Finland) in collaboration with Aalto University (Finland), UNSW (Australia) and University of Chicago (United States) have demonstrated how some of the most counterintuitive predictions of quantum mechanics can be verified in nearly-macroscopic objects.

They have shown 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 provides new tools for the technological applications, especially a widespread intrinsically secure communication.

Postdoctoral researcher Asjad Muhammad from Department of Physics at the University of Jyväskylä said, “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.”

Researcher group leader Academy Research Fellow Francesco Massel from Department of Physics at the University of Jyväskylä said, “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.”

Scientists work is described in the journal Nature.