Proposed test of quantum superposition measures 'quantum revivals'

Physicists have proposed an entirely new way to test the quantum superposition principle—the idea that a quantum object can exist in multiple states at the same time. The new test is based on examining the quantum rotation of a macroscopic object—specifically, a nanoscale rotor, which is considered macroscopic despite its tiny size.

Until now, most tests of quantum superposition have been based on linear, rather than rotational, motion. By examining rotational motion, the new test may lead to applications such as quantum-enhancedtorquesensing, and could provide insight into a variety of open questions, such as what causes the quantum wave function to collapse.

The physicists, led by Klaus Hornberger at the University of Duisburg-Essen, Germany, have published a paper on the proposed test in a recent issue of the New Journal of Physics.