A big step forward in quantum computing has just been announced: the first ever quantum circuit

Australian scientists have created the world’s first quantum computer circuit – one that contains all the basic components found in a classical computer chip but on a quantum scale.

The historical discovery was published in temper nature Today, nine years were in the making.

“This is the most exciting discovery of my career,” said Michelle Simmons, lead author, quantum physicist, and founder of Silicon. Quantitative Statistics and Director of the Center of Excellence for Quantum Computation and Communications Technology at the University of New South Wales for ScienceAlert.

Not only have Simmons and her team created what is essentially a functional quantum processor, they have also successfully tested it by modeling a small molecule per atom of multiple quantum states — something a classical computer would struggle to achieve.

This suggests that we are now one step closer to finally using the power of quantum processing to understand more about the world around us, even on the smallest scale.

In the 1950s, Richard Feynman “We will never understand how the world works — how nature works — unless we can actually start making it on the same scale,” Simmons said.

“If we can begin to understand materials at this level, we can design things that have never been made before.

“The question is: How do you really control nature at this level?”

The latest invention comes after the team created the first quantum transistor in 2012.

(a transistor It is a small device that controls electronic signals and forms only one part of a computer circuit. The integrated circuit is more complex because it brings so many transistors together.)

To make this leap in quantum computing, the researchers used a scanning tunneling microscope in a very high vacuum to position quantum dots precisely under a nanometer.

The placement of each quantum dot must be absolutely correct so that the circuit can simulate how electrons jump along a chain of single- and double-bonded carbons in a polyacetylene molecule.

The hardest parts were figuring out: exactly how many phosphorous atoms should be in each quantum dot; Exactly how far apart each point should be; Then engineer a machine that can place the tiny dots in exactly the right order inside the silicon chip.

If the quantum dots are too large, the researchers say, the interaction between two dots becomes “too large to be controlled independently.”

If the dots are too small, it introduces randomness because each additional phosphorous atom can drastically change the amount of energy needed to add another electron to the dot.

The final quantum chip contained 10 quantum dots, each consisting of a small number of phosphorous atoms.

Carbon double bonds were simulated by placing less distance between the quantum dots compared to the single carbon bonds.

Polyacetylene was chosen because it is a popular model and can therefore be used to demonstrate that a computer was correctly simulating the movement of electrons through the molecule.

Quantum computers It is needed because classical computers cannot model large molecules; They are just too complicated.

For example, to create a simulation of a penicillin molecule with 41 atoms, a classical computer would need 1086 transistors, which areThere are more transistors than atoms in the observable universe“.

For a quantum computer, it only requires a processor with an extension 286 Qubits (quantum bits).

Since scientists currently have limited insight into how molecules work at the atomic level, there is a lot of guesswork in creating new materials.

“One of the Holy Grails has always caused the temperature to rise superconductorSimmons says. People don’t know the mechanism of how it works. ”

Another potential application of quantum computing is the study of artificial photosynthesis, how light is converted into chemical energy through an organic series of reactions.

Another big problem that quantum computers can help solve is the fertilizer industry. Currently, nitrogen triple bonds are broken under conditions of high temperature and pressure in the presence of an iron catalyst to form fixed nitrogen for fertilizers.

Finding a different catalyst that can make composting more effective can save a lot of money and energy.

Simmons says that achieving the transition from quantum transistor to circuit in just nine years mimics the roadmap laid out by the inventors of classical computers.

The first classical computer transistor was created in 1947. The first integrated circuit was built in 1958. These two inventions are 11 years apart. The Simmons made that leap two years ahead of schedule.

This article was published in temper nature.

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