Theoretical physicist **Carlos Sabin** of the Autonomous University of Madrid (UAM) has carried out a **simulation** in a **IBM quantum computer** that could be useful on the way to proving that gravity is a quantum force.

Although an actual experiment has not yet been performed, this advance is a step toward a better understanding of the **quantum nature of gravity**.

The study, published in the journal *EPJ Quantum Technology*reveals how experimental groups could use these findings to empirically verify the quantum character of the gravitational field.

Experimental groups could use the results of this simulation to empirically verify the quantum character of the gravitational field.

"While the **experimental proposals** to generate entanglement through gravity are still beyond our current technological capabilities, it is conceivable that this will change in a few years, says Sabin.

"This evolution would allow direct verification of the quantum aspects of gravity," he adds, "but in the meantime, I have turned to one of IBM's quantum computers to simulate these experiments.

## Towards a quantum theory of gravity

To date, we do not have a **quantum theory of gravity**unlike other fundamental forces such as electromagnetism. There are theoretical proposals, such as the famous **string theory**but its experimental verification remains beyond the reach of current technologies.

Recently, a more modest approach has been developed which aims to simply demonstrate the **quantum nature of gravity**without the need to reveal all the underlying quantum theory.

This approach is based on the idea that, if we manage to generate **quantum entanglement** between systems governed by quantum physics through purely gravitational means, we may be able to confirm that the **gravity** is, in fact, a **quantum force**even without knowing the complete theory.

If quantum entanglement between systems governed by quantum physics is achieved through gravitational means, it could be confirmed that gravity is a quantum force.

"He **entanglement** is the term we use to describe certain correlations between measurement results that are only possible in quantum systems. These correlations are extremely useful for the development of new technologies, including quantum computers," explains Sabin.

As part of his research, Sabin translated the results of a specific experiment - conducted by scientists at University College London (UK) and the University of Groningen (The Netherlands) - into the language of the **quantum bits (cubits)** and the transformations between them (**quantum logic gates**). He then implemented the simulation over the Internet on a quantum computer and analyzed the results, comparing them with theoretical ideals.

"Using modern techniques to 'mitigate' experimental errors, I have found that the results obtained are practically identical to the theoretical ones. This indicates that the entanglement generated between the cubits would be equivalent to that which would have been generated by gravity between quantum systems in a real experiment," concludes the researcher.