quantum computers tagged posts

Engineers make Critical Advance in Quantum Computer Design

Dr Jarryd Pla and Prof. Andrew Dzurak look from behind a transparent screen showing mathematical workings
Dr Jarryd Pla and Professor Andrew Dzurak have solved the problem of how to reliably control not just a few, but millions of qubits. Photo: UNSW

Quantum engineers from UNSW Sydney have removed a major obstacle that has stood in the way of quantum computers becoming a reality. They discovered a new technique they say will be capable of controlling millions of spin qubits—the basic units of information in a silicon quantum processor.

Until now, quantum computer engineers and scientists have worked with a proof-of-concept model of quantum processors by demonstrating the control of only a handful of qubits.

But with their latest research, published today in Science Advances, the team have found what they consider “the missing jigsaw piece” in the quantum computer architecture that ...

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A Speed Limit also applies in the Quantum world

A speed limit also applies in the quantum world
First author Manolo Rivera Lam (left) and principal investigator Dr. Andrea Alberti (right) at the Institute of Applied Physics at the University of Bonn. Credit: © Volker Lannert/Uni Bonn

Even in the world of the smallest particles with their own special rules, things cannot proceed infinitely fast. Physicists at the University of Bonn have now shown what the speed limit is for complex quantum operations. The study also involved scientists from MIT, the universities of Hamburg, Cologne and Padua, and the Jülich Research Center. The results are important for the realization of quantum computers, among other things. They are published in the prestigious journal Physical Review X, and covered by the Physics Magazine of the American Physical Society.

Suppose you observe a waiter (the...

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New Algorithm could Unleash the Power of Quantum Computers

A new algorithm leaps past limits restricting quantum computers.
A new algorithm leaps past limits restricting quantum computers.

Fast-forwarding quantum calculations skips past the time limits imposed by decoherence, which plagues today’s machines. A new algorithm that fastforwards simulations could bring greater use ability to current and near-term quantum computers, opening the way for applications to run past strict time limits that hamper many quantum calculations.

“Quantum computers have a limited time to perform calculations before their useful quantum nature, which we call coherence, breaks down,” said Andrew Sornborger of the Computer, Computational, and Statistical Sciences division at Los Alamos National Laboratory, and senior author on a paper announcing the research...

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Scientists use Light to Accelerate Supercurrents, access Forbidden Light, Quantum World

This illustration shows light wave acceleration of supercurrents, which gives researchers access to a new class of quantum phenomena. That access could chart a path forward for practical quantum computing, sensing and communicating applications. Larger image. Image courtesy of Jigang Wang.

Scientists are using light waves to accelerate supercurrents and access the unique properties of the quantum world, including forbidden light emissions that one day could be applied to high-speed, quantum computers, communications and other technologies.

The scientists have seen unexpected things in supercurrents – electricity that moves through materials without resistance, usually at super cold temperatures – that break symmetry and are supposed to be forbidden by the conventional laws of physic...

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