Scientists have used the latest research in quantum computing and quantum technology to pioneer a radical new approach to determining how our Universe functions at its most fundamental level.

An international team of experts, led by the University of Nottingham, have demonstrated that only quantum rather than classical gravity can be used to create a particular computational component that is needed for quantum computing. Their research “Non-Gaussianity as a signature of a quantum theory of gravity” was published on February 17, 2021, in *If PRX*.

Dr. Richard Howl led the research during his time at the School of Mathematics at the University of Nottingham, he said: “For more than a hundred years, physicists have struggled to determine how the two basic theories of science, quantum theory and general relativity, which respectively describe microscopic and macroscopic phenomena, are unified in a single comprehensive theory of nature.

During this time, they have come up with two fundamentally opposite approaches, called ‘quantum gravity’ and ‘classical gravity’. However, a complete lack of experimental evidence means that physicists do not know which approach the general theory takes, our research provides an experimental approach to solving this. “

This new research, which is a collaboration between experts in quantum computing, quantum gravity and quantum experiments finds an unexpected connection between the fields of quantum computing and quantum gravity and uses this to propose a way to prove experimentally that non-classical quantum gravity exists. The suggested experiment would involve cooling billions of atoms in a millimeter-sized spherical trap at extremely low temperatures, such that they enter a new phase of matter, called a Bose-Einstein condensate, and begin to behave as a quantum atom. Then a magnetic field is applied to this “atom” so that it only senses its gravitational pull. With everything in place, if the single gravitational atom demonstrates the key component needed for quantum computing, which is curiously associated with “negative probability,” nature must take the quantum gravity approach.

This proposed experiment uses current technology, involves only a single quantum system, the gravitational “atom” and does not rely on assumptions about the locality of the interaction, making it simpler than previous approaches and potentially speeding up test delivery first experimental of quantum gravity. Physicists would then have, after more than a hundred years of research, finally information on the true basic theory of nature.

Dr. Marios Christodoulou, from the University of Hong Kong who was part of the collaboration, added: “This research is particularly exciting as the proposed experiment would also relate to the more philosophical idea that the universe is behaving like a large quantum computer that is calculating itself. , demonstrating that quantum fluctuations in space-time are a vast natural resource for quantum computing. “

The research brought together experimental and theoretical physicists from a range of international disciplines and research institutions. Other authors are: Richard Howl, Vlatko Vedral (Oxford and Singapore), Devang Naik (CNRS, Bordeaux), Marios Christodoulou (Hong Kong and Oxford), Carlo Rovelli (Marseille) and Aditya Iyer (Oxford).

Reference: “Non-Gaussianity as a Signature of a Quantum Theory of Gravity” by Richard Howl, Vlatko Vedral, Devang Naik, Marios Christodoulou, Carlo Rovelli and Aditya Iyer, 17 February 2021, *If PRX*.

DOI: 10.1103 / PRXQuantum.2.010325