The coat of arms of the Italian aristocratic Borromean family contains disturbing symbols. It is an arrangement of three connected rings that cannot be pulled apart but contain no linked pairs.
Coupling in the same three directions is the undisputed hallmark of one of the most coveted phenomena in quantum physics, and has been observed for the first time. The researchers used a quantum computer to create virtual particles and move their paths in a Borromian ring pattern.
Exotic particles are called non-Abelian anyons, or non-Averyons for short, and their Borromian rings exist only as information within a quantum computer. But their link properties could help make quantum computers less error-prone or more “fault-tolerant.” Results revealed in May 9 preprint1obtained on machines at Quantinuum, a quantum computing company in Bloomfield, Colorado.
Tony Uttley, President and Chief Operating Officer of Quantinuum, said:
Other researchers aren’t optimistic about the potential of virtual non-Abellions to revolutionize quantum computing, but creating them is seen as an achievement in itself. “There is immense mathematical beauty in this type of physical system, and it’s amazing that it’s only been realized after so many years,” says Stephen Simon, a theoretical physicist at the University of Oxford, UK. says.
basket weave donuts
For this experiment, Henrik Dreyer, a physicist at the Quantinuum office in Munich, Germany, and his collaborators used the company’s state-of-the-art machine, called H2. The machine is equipped with a chip that can generate an electric field to trap his 32 ions of the element ytterbium on the surface. Each ion can encode a qubit, a unit of quantum computation that can be ‘0’ or ‘1’ like a normal bit, but both states can be superimposed at the same time.
Quantinuum’s approach has its advantages. Compared to most other types of qubits, ions in the trap can be moved and interacted with. This is how quantum computers perform computations.
Physicists have used this flexibility to create an unusually complex form of quantum entanglement, in which all 32 ions share the same quantum state. By manipulating these interactions, we created a virtual entangled lattice with a kagome structure. This is used in the Kagome structure. The pattern resembles a repeating six-pointed star on top of each other, folded to form a donut shape. The entangled state represents the lowest energy state of the virtual 2D universe. In other words, it contains no particles at all. However, with further manipulation, Kagome can be brought into an excited state. These correspond to the appearance of particles that should have non-Abellion properties.
To prove that the excited state is non-Abellion, the team performed a series of tests. The most decisive was moving excited states to create virtual Boromian rings. The pattern’s emergence was confirmed by measuring ion conditions during and after surgery, Dreyer said.
Ashvin Vishwanath, a theoretical physicist at Harvard University in Cambridge, Massachusetts, and co-author of the paper, said: “It’s a really amazing state of matter, and it’s not very clearly perceived in other setups.”
Michael Manfra, an experimental physicist at Purdue University in West Lafayette, Indiana, says that although the results are impressive, the Quantinuum machine does not truly create non-Abellions, but only simulates some of their properties. It is said that However, the authors say that the behavior of particles meets the definition, and that for practical purposes particles can still form the basis of quantum computing.
what a pedigree
Like the Borromean family, Nonaberion comes with a storied family tree in both physics and mathematics, including work that has led to several Nobel and Fields Medals. A nonnabellion is a type of anyon, a particle that can only exist in a 2D universe or in a situation where matter is confined to a 2D surface (such as the interface of two solid materials).
Anyons violates one of the most important assumptions of physicists: that all particles belong to one of two categories: fermions or bosons. When two identical fermions switch positions, their quantum states, called wavefunctions, flip 180 degrees (in a mathematical space called Hilbert space). But when the boson switches, the wavefunction does not change.
On the other hand, when two anyons are switched, neither of these two options apply. Instead, in standard “Abelian” anyons, the wavefunction is shifted by a certain angle, different from 180 degrees in fermions. Non-abelian anyons respond by altering their quantum states in more complex ways. This is very important as we need to be able to perform quantum computations that are non-abelian. In other words, the calculations produce different results when executed in different orders.
Topology Robustness
Nonabelions may also outperform most other methods of performing quantum computing. The information in individual qubits typically degrades rapidly and is prone to errors. This is what limits progress towards useful quantum computing. Physicists have developed a variety of error correction schemes that require qubits to be encoded in collective quantum states of many atoms, potentially thousands of atoms.
But nonabelion should make that task much easier. Because the paths you take while looping over each other must be robust against errors. Perturbations such as magnetic perturbations can shift the paths slightly without changing the qualitative property of the links, called topology.
The concept of non-Abellions and their potential as ‘topological qubits’ was first proposed 20 years ago by theoretical physicist Alexei Kitaev (now at Caltech, Pasadena).2Physicists, including Manfra, have sought to create states of matter that naturally contain non-avaion and can serve as platforms for topological qubits. Microsoft makes topological qubits the preferred approach for developing quantum computers.
Vishwanath says the nonabelion of Quantinuum’s machine is an important first step. “To be in that game, to be a candidate for a topological quantum computer, the first necessary step is to create such a state,” he says.
Simon says the hypothetical non-Abellion approach could be useful for quantum computing, but says it remains to be seen if it is more efficient than other error-correction schemes. Physical anyons, which both Manfra and Microsoft are working on, will soon be topologically robust. Dreyer says it’s still unclear how efficient his nonabelions on his team are at this point.
This article is reproduced with permission and was first published on May 9, 2023.
