Is It Possible to Prepare Quantum States of “Heavy” Objects?

A new project at DTU Physics has set out to examine whether heavy objects like cantilevers and springs can be steered into quantum states. The question is one of the most intriguing questions in contemporary physics and a positive answer means completely new possibilities in quantum physics and sensor technologies.

quantum states

Professor Ulrik Lund Andersen from DTU Physics has just received a grant of 7 million DKK from the VILLUM Foundation to study the possibility of steering macro mechanical objects into quantum states using nonclassical light.

If the ambitious project succeeds, it will empower the capabilities of optomechanics, which is the branch of science dealing with the interaction between light and mechanical objects. Among others, it will:

– affect the theoretical descriptions of quantum mechanics and the coupling to the theory of relativity.

– allow new experiments in the development of quantum information technologies.

– enable the development of revolutionary new sensing techniques with unprecedented levels of sensitivity in acceleration measurements, in atomic force microscopy and in magnetometry.

“Mechanical oscillators such as micron-sized cantilevers can be driven into strange, non-classical motional states through the interaction with light. By using light it is possible to steer the oscillator into a state where its position is at two places at the same time. The formation of such exotic states of a massive oscillator will probe physics in a completely new regime, and might lead to a deeper understanding of the yet scarcely studied interface between quantum mechanics and general relativity”, explains L. Andersen.

So far, scientists worldwide have used laser light, i.e. classic light behaving as we know it from other visible light. But despite significant interest, the light-induced formation of nonclassical states has not yet been realized experimentally due to the strict requirement of a strong, and currently unattainable, interaction between light and mechanics.

“In this project we will overcome the problem by using a radically different approach that does not rely on strong coupling. We will use nonclassical light to measure and to steer mechanical oscillators into the realm of quantum mechanics. Using squeezed states and photon-subtracted squeezed states as well as state-of-the art micro-mechanical systems and high-efficiency photo detectors, we want to prepare highly exotic quantum states of the mechanical oscillator.

As part of the project the DTU researchers will work across disciplines and collaborate with some of the world’s leading research groups with complementary expertises.