Colliding top quarks reveal hidden quantum magic

Queen Mary University of London physicist Professor Chris White, along with his twin brother Professor Martin White from the University of Adelaide, have discovered a surprising connection between the Large Hadron Collider (LHC) and the future of quantum computing.

For decades, scientists have been striving to build "quantum computers" that leverage the bizarre laws of quantum mechanics to achieve far greater processing power than traditional computers. A recently identified property – amusingly called "magic" - is critical for building these machines, but its generation and enhancement remain a mystery. 

For any given quantum system, magic is a measure that tells us how hard it is to calculate on a non-quantum computer. The higher the magic, the more we need quantum computers to describe the behaviour. Studying the magic properties of quantum systems generates profound insights into the development and use of quantum computers. 

This new research, published in Physical Review D, demonstrates for the first time that the LHC routinely produces "magic." By studying the behaviour of top quarks, the heaviest known fundamental particles, produced at the LHC, the researchers have predicted that "magic top quarks" will be made very often. Interestingly, the amount of "magic" exhibited by these top quarks depends on how fast they are moving and their direction of travel, all of which can be measured by the ATLAS and CMS detectors that observe the results of the LHC proton collisions.

This discovery holds significant implications for understanding and potentially enhancing magic in other quantum systems. "While entanglement, where particles become linked, has been a major focus of quantum research," explains Professor Chris White, "our work explores the concept of 'magic' in top quarks, which essentially measures how well-suited particles are for building powerful quantum computers." Professor Martin White adds “The ATLAS experiment has already observed evidence of quantum entanglement. We have shown that the LHC can also observe more complex patterns of quantum behaviour, at the highest energies yet attempted for these kinds of experiments”.

The potential benefits of quantum computers are vast, impacting fields like drug discovery and materials science. However, harnessing this power requires robust and controllable quantum states, and "magic" plays a critical role in achieving that control.

The White brothers’ research paves the way for a deeper understanding of the connection between quantum information theory and high-energy physics. "By studying 'magic' in top quark production,"  Professor Chris White says, "we create a new bridge between these two exciting areas of physics." Furthermore, this research highlights the potential of the LHC as a unique platform for exploring the frontiers of quantum theory.

This discovery is not just about the heaviest particles in the universe; it's about unlocking the potential of a revolutionary new computing paradigm.