LeGaNa · Leggett-Garg test of a vibrating carbon nanotube

Leggett-Garg test of a vibrating carbon nanotube

Despite the undeniable success of quantum mechanics, the boundary between quantum and classical mechanics remains unclear. This problem is encapsulated in one of the most famous thought experiments in science, the Schrödinger’s Cat scenario: since quantum superposition is necessary to describe the atomic scale, must it also apply to everyday objects? This is a question that has now moved beyond thought experiments. Theoretical work by Leggett and Garg provided a script for experiments to determine whether an object is at all times in one of its distinct states or whether quantum superposition prevails. This script has been used to demonstrate unambiguous superposition of microscopic objects whose quantum nature was already well-established, such as photons and electrons. Making use of a vibrating carbon nanotube with ~10^5 atoms, the question is: does superposition apply also to mesoscopic objects? Extending quantum control to increasingly macroscopic systems will not only help to answer crucial questions in the foundations of quantum theory, but will also enable quantum superposition and entanglement to be harnessed for new applications. The overall objective is to demonstrate quantum behaviour beyond the most microscopic system on a vibrating carbon nanotube.

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