# To control quantum computing || کوانٹم کمپیوٹنگ faults, a new form of quasiparticle is developed.

The Achilles heel of quantum computation is errors, which can appear at any time and endanger calculations. However, they may theoretically be controlled by embedding quantum information in a particular kind of quasiparticle known as a non-Abelian anyone. Now, independently published findings from teams at Google, Microsoft, the quantum computer company Quantinuum, and Zhejiang University in China suggest that such quasiparticles may exist.

According to Jianlis Pathos, a physicist at the University of Leeds in the UK, the latest studies “make a very intriguing advance in** quantum computing || کوانٹم کمپیوٹنگ**” Steven Simon, a theorist at the University of Oxford in the UK, concurs, saying, “They are all things we have been waiting to see for a long time.” “The field is in a very exciting period during this time. However, Simon cautions that none of the discoveries will immediately transform quantum computing. They all have flaws, so there is definitely space for improvement, he claims.

## Quantum computing mistakes

Quantum bits, or qubits, which can have a value of 1, 0, or a superposition of the two, are used by quantum computers to store binary information. Qubits are a class of physical systems that include ions, photons, and minute parts constructed of superconducting material. Entangling several qubits makes their states interdependent, which allows for quantum calculations to be done by manipulating them in accordance with an algorithm before reading out their final states.

The problem is that throughout the computation, qubit states might vary due to random noise in the environment, which reduces the accuracy of the calculation. This can also occur with traditional computers, although in those cases the issue can be easily fixed, for instance by maintaining several copies of each bit and determining its value using the majority rule. Qubits, on the other hand, cannot be copied because quantum physics forbids it and quantum computing, by its very nature, demands that the qubit states stay unknown throughout the calculation. Researchers have been forced to look for trickier techniques for mistake correction as a result.

### Saved by Majorana particles

Using additional error-resistant qubits is an alternate strategy. Physicist Alexei Kitao demonstrated that it would be feasible to construct error-protected qubits using fictitious things known as Majorant particles in a work authored in 1997 (and published in 2003). These particles, which were first hypothesized in 1937 by the scientist Ettore Majorant, have an odd characteristic in that they are their own antiparticle.

quantum computing || کوانٹم کمپیوٹنگ The existence of Majoring particles as basic particles is unknown. However, Kite demonstrated that they may theoretically be produced from electron collective states known as quasiparticles. Additionally, he demonstrated that these states would be “topologically protected” if utilized as qubits, which means that noise cannot randomly flip them without “breaking” the quasiparticle, much as it cannot remove the twist in a Möbius strip without cutting it. In a later statement, Kite suggested that these Majorcan quasiparticles may be created as electronic defect states at the ends of quantum nanowires built of (for instance) a semiconductor located close to a superconductor.

These hypothetical (quasi)particles are referred to as non-Abelian anyone and constitute a subclass of defect states known as Majorant zero modes (MZMs). The term anyone denotes a particle that is neither a fermion nor a boson, which was a trait that physicist Frank Walczak hypothesized in 1982 and which researchers from the US and France finally discovered in electronic quasiparticles in 2020. But unlike the non-Abelian kind Kite suggested for error-protected qubits, those findings were of Abelian anyone. In particular, even if the particles themselves are identical, when two non-Abelian anyone switch positions, their quantum states alter in a way that can be seen. In contrast, Abelian anyone only experience a change in their quantum phase rather than any other observable alteration.

#### The complex web we spin

Kitale suggested moving the non-Abelian anyone and weaving their trajectories together to produce qubits. The anyone are able to switch positions in a way that modifies their visible states through the weaving process known as braiding. Then, you may utilize this to carry out a logic operation. Thus, implementing a quantum algorithm includes braiding non-Abelian anyone in a certain manner and reading the outcome.

quantum computing || کوانٹم کمپیوٹنگ The fundamental advantage of this configuration is that the braiding’s topology essentially “remembers” the qubit states. Only when a braid is cut, which takes a lot of energy, may errors occur. The calculation is referred to be topologically error-corrected in these instances.

2018 saw the simulation of the braiding of non-Abelian MZMs in a single three-state (qutrit) optical system by researchers in China and the UK, including Pathos. The three quantum states in that experiment were corresponding to photon polarization levels. The most recent findings go one step further by demonstrating how to apply the concept to actual many-qubit quantum circuits

##### The challenging process of creating MZMs

Microsoft has staked its quantum computing future on creating topologically protected qubits from MZMs, whereas many other organizations have continued to work on building quantum computers using traditional, non-Majorant qubits Quantum error-correcting codes provide as support. In Santa Barbara, California, Chetan Nayak of Microsoft Quantum stated that “Microsoft’s long-standing belief is that engineering an error-protected topological qubit is the path to delivering quantum computing at The researchers assert that by implementing a topological qubit in hardware, “we will be able to develop a new class of qubit that is quick, compact, and controllable.”

However, this has proven to be quite challenging, and the area has been plagued with assertions that have later fallen apart under close examination. Finding a distinctive MZM signal that sets them apart from other quasiparticles has been one of the challenges. Nayak and colleagues present data in their most recent publication to support what they believe to be a MZM discriminating criterion. The topological gap protocol is a requirement, and according to Microsoft researchers, their technology, which consists of a thin sheet of semiconducting indium arsenide resting underneath a 120 nanometer-wide strip of superconducting aluminum, meets it.

**Anyons or anyon simulations?**

Teams from Quantinuum (previously Honeywell Quantum Solutions and Cambridge Quantum Computing) in Germany, Zhejiang University in Hangzhou, China, and Google Quantum AI in the United States are concurrently working on this. and the US all claim to have created non-Abelian anyone from clever combinations of more conventional qubits — superconducting circuits for the Google and Zhejiang groups, and trapped ions for Quantinuum — respectively.

The definition of the term “made” is at issue here. One may argue that all three conclusions utilize quantum simulations of particles rather than actual particles themselves, which is analogous to simulating atoms on a conventional computer. But the line between the two is hazy. Qubits can be utilized to create the exact same quantum wavefunction that an anyone would have because they are quantum objects in and of themselves. The line between mimicking matter and really possessing matter is blurry, according to Simon. However, they can be certain that they have created the desired wavefunction.

The Google and Zhejiang teams used comparable techniques to a 25-qubit semiconductor and a 68-qubit array, respectively. Similar to dislocations in a crystal lattice, the anyone in both experiments are flaws in a square lattice of interacting qubits. This lattice structure’s lowest-energy (ground) state is made up of wavefunctions that correspond to Abelian anyone as Kitao showed, this alone may be utilized to create an error-correcting qubit that is protected by an error-correcting code known as the surface code.

###### a another path to non-Abelian beings

While this was going on, the Quantinuum group developed non-Abelian anyone in a different approach. They developed a quasi-one-dimensional chain of interacting trapped-ion qubits using the Honeywell 32-qubit H2 quantum processor, which traps ytterbium ions in an electromagnetic field and modifies their quantum states using lasers.

quantum computing || کوانٹم کمپیوٹنگ In this case, the anyone are natural excitations of the qubit system’s ground state, making them technically not quasiparticles because quasiparticles need excited states. The Majorant zero modes at the ends of superconducting wires in the Microsoft experiment and the lattice defects in the Google experiment are non-Abelian defects emphasizes Ashwin Vishwanath of Harvard University, who worked with the Quantinuum team. They are not realized on top of true non-Abelian topological order in contrast to our experiment.

However, according to Chris Monroe, a physicist at Duke University in North Carolina, US, and the business Ion’s principal scientist, all three outcomes are neat quantum simulations. Such studies, he continues, could have certainly been carried out on quantum computing platforms years ago, but they were presumably spurred on by the recent interest in and debate over MZMs in solid-state systems. It’s an intriguing intersection of science and sociology, he claims.

## Reference

https://physicsworld.com/a/new-type-of-quasiparticle-emerges-to-tame-quantum-computing