Quantum computers will get conventional displays and lasers: how the new technology works

A quantum computer built from ordinary and easily available components could stimulate quantum research in many parts of the world.

Scientists from the University of the Witwatersrand in Johannesburg (Wits University) propose creating a quantum computer made using conventional hardware. Interesting Engineering writes about this.

Building quantum computers is extremely expensive, often costing millions of dollars, due to the need to use specialized materials, components, and equipment such as cryogenic systems and advanced electronics.

This is one of the reasons why scientists in only a few developed parts of the world currently have access to this advanced computing technology.

It may seem incredible, but the authors of the study built a quantum computer using only laser beams, digital displays (like those used in projectors), and simple lenses. The computer successfully completed complex tasks and processed several levels of information beyond the capabilities of classical computers.

The researchers' quantum computer is driven by the properties of light. They used classically structured light, a type of light beam that is manipulated to give it specific shapes, structures, or phases, allowing it to carry complex information.

By applying quantum principles such as superposition of states (where a system can operate in multiple states at once), the researchers performed photonic matrix multiplication — a process in which light patterns are used to perform mathematical operations on matrices.

After classically structured light was successfully integrated with the optical components of a computer, the researchers tested their quantum system using the Deutsch-Johgi algorithm.

This particular algorithm solves a specific problem: determining whether a function is constant (produces the same output for all inputs) or balanced (produces different outputs for half of the inputs). It may seem simple, but this algorithm shows whether a system is faster, better, and more efficient than a classical computer.

When the researchers tested their quantum computer, its performance surprised them because, like an expensive quantum system, their innovation far outperformed classical computers.

What's more, because this quantum computer uses light to process information, the speed at which it can perform multiple complex calculations simultaneously is unparalleled.