# Compounding a set of 3 silicon quantum dots, a group of Japanese researchers made a breakthrough in the quantum computing industry

- Tram Ho

In the future, quantum computers will operate with higher performance than traditional computers, but this is not the story for now. With a new breakthrough made by Japanese physicists, bringing three silicon quantum dots into entanglement for the first time, the dream of “quantum supremacy” is one step closer.

Quantum computers take advantage of the bizarre interactions of the microscopic world, they can store and use three data states simultaneously (0; 1 and at the same time 0 and 1) to quickly perform complex maths. We can manipulate these matter particles in many ways, and the method of “quantum entanglement” is one of the techniques that helps us to have a superior computer.

The quantum entangled microscopy gate with another quantum dot, creates a pair of three entangled qubits.

The quantum entanglement causes two matter particles to be closely bound, giving the same measurement results no matter how far apart. It surprised geniuses like Albert Einstein, calling it “bizarre activity at a distance” and saying that’s why the theory of quantum mechanics has yet to be agreed upon.

In quantum computers, quantum entanglement allows data to be transmitted faster, while improving data error correction. Qubits, the basic unit of quantum information, are often tangled together in pairs. But in the new experiment, a team of experts at the RIKEN research center for matter science succeeded in quantum entanglement of three qubits, which are three silicon particles.

The new experiment uses qubits made from tiny rings of silicon called quantum dots. They are prime candidates for making qubits for quantum computers not only because silicon is widely used in electronics, but also because the microscopic silicon ring is more stable, easier to control, and more active. operates at a more viable temperature range and has the potential to scale up relatively easily.

## Tackling the three silicon qubits again is an important step towards achieving all of these strengths. The Japanese experiment will surpass the previous breakthrough, which was to quantum entangle three photons together.

“ *Instructions using two qubits are enough to perform basic logical operations. But a system of three entangled qubits would be the minimum unit for which we can scale up the system and apply error correction* ,” said study author Seigo Tarucha.

The team made the breakthrough, with study author Seigo Tarucha second from right.

The new device is made of three quantum dots, controlled by a microscopic gate made of aluminum. Each quantum dot contains only one electron, used to represent the values 0 and 1 in the binary system as they rotate in certain directions. Wrapping them all up is a magnetic field gradient that separates the frequencies of the qubits, allowing scientists to measure each qubit individually.

To entangle 3 qubits, the team began to tangle a pair first with a quantum computing device through a 2-qubit gate. Then they messed up the third qubit with the gate itself. The result is an array of 3 qubits with an accuracy of up to 88%, which means that the percentage of qubits in the “right” state when measured is very high.

This quantum entanglement technique will be effectively applied in error correction. With quantum computers, qubits tend to randomly lose state, causing the data stored on them to disappear. The normal computer error correction method cannot be applied to quantum computers. Each quantum computer research institution will use a different type of error correction, such as an array of self-monitoring qubits or error correction with tangle-free qubits. The Japanese team uses a set of three quantum entangled qubits.

” *We intend to demonstrate error correction using a three-qubit device, and to simulate a device with a qubit count of 10 or more,* ” said Professor Tarucha. “ *Next will be the development of systems from 50 to 100 qubits and the application of even more complex error correction methods, paving the way for large-scale quantum computer development within the next decade* .”

*According to RIKEN*

**Source : ** Genk