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Category: quantum physics – Page 833

The Los Alamos nuclear weapons lab just bought a 5,000-qubit quantum computer

D-Wave today announced its next generation “Advantage” quantum computer system. It’ll pack a whopping 5,000 qubits and myriad improvements to processing speed and power. And the Los Alamos National Laboratory in New Mexico will be among the first to have access.

According to a press release from D-Wave, the new Advantage system improves on the previous generation’s 2000Q model – which sports a paltry-by-comparison 2,048 qubits – in nearly every conceivable way:

Designed to speed the development of commercial quantum applications, the Advantage quantum system will power a new hardware and software platform that will accelerate and ease the delivery of quantum computing applications. Reflecting years of customer feedback, the platform captures users’ priorities and business requirements and will deliver significant performance gains and greater solution precision.

2000 atoms in two places at once: A new record in quantum superposition

The quantum superposition principle has been tested on a scale as never before in a new study by scientists at the University of Vienna in collaboration with the University of Basel. Hot, complex molecules composed of nearly two thousand atoms were brought into a quantum superposition and made to interfere. By confirming this phenomenon—” the heart of quantum mechanics,” in Richard Feynman’s words—on a new mass scale, improved constraints on alternative theories to quantum mechanics have been placed. The work will be published in Nature Physics.

Quantum to classical?

The superposition principle is a hallmark of quantum theory which emerges from one of the most fundamental equations of quantum mechanics, the Schrödinger equation. It describes particles in the framework of wave functions, which, much like on the surface of a pond, can exhibit . But in contrast to water waves, which are a collective behavior of many interacting , quantum waves can also be associated with isolated single particles.

Google researchers have reportedly achieved “quantum supremacy”

The news: According to a report in the Financial Times, a team of researchers from Google led by John Martinis have demonstrated quantum supremacy for the first time. This is the point at which a quantum computer is shown to be capable of performing a task that’s beyond the reach of even the most powerful conventional supercomputer. The claim appeared in a paper that was posted on a NASA website, but the publication was then taken down. Google did not respond to a request for comment from MIT Technology Review.

Why NASA? Google struck an agreement last year to use supercomputers available to NASA as benchmarks for its supremacy experiments. According to the Financial Times report, the paper said that Google’s quantum processor was able to perform a calculation in three minutes and 20 seconds that would take today’s most advanced supercomputer, known as Summit, around 10,000 years. In the paper, the researchers said that, to their knowledge, the experiment “marks the first computation that can only be performed on a quantum processor.”

Quantum speed up: Quantum machines are so powerful because they harness quantum bits, or qubits. Unlike classical bits, which are either a 1 or a 0, qubits can be in a kind of combination of both at the same time. Thanks to other quantum phenomena, which are described in our explainer here, quantum computers can crunch large amounts of data in parallel that conventional machines have to work through sequentially. Scientists have been working for years to demonstrate that the machines can definitively outperform conventional ones.

Ghost post! Google creates world’s most powerful computer, NASA ‘accidentally reveals’ …and then publication vanishes

Google’s new quantum computer reportedly spends mere minutes on the tasks the world’s top supercomputers would need several millennia to perform. The media found out about this after NASA “accidentally” shared the firm’s research.

The software engineers at Google have built the world’s most powerful computer, the Financial Times and Fortune magazine reported on Friday, citing the company’s now-removed research paper. The paper is said to have been posted on a website hosted by NASA, which partners with Google, but later quietly taken down, without explanation.

Google and NASA have refused to comment on the matter. A source within the IT giant, however, told Fortune that NASA had “accidentally” published the paper before its team could verify its findings.

Viewpoint: Cold Atoms Bear a Quantum Scar

Theorists attribute the unexpectedly slow thermalization of cold atoms seen in recent experiments to an effect called quantum many-body scarring.

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Researchers still have some way to go before they can assemble enough quantum bits (qubits) to make a practical, large-scale quantum computer. But already the best prototypes, made up of several tens of qubits, are opening our eyes to new behavior in the quantum realm. Last year, a team from Harvard University and the Massachusetts Institute of Technology (MIT) unveiled a quantum “simulator” made up of a row of 51 interacting atoms [1]. Exciting the individual atoms in various patterns (Fig. 1), they discovered something unexpected: atoms in certain patterns took at least 10 times longer to relax towards thermal equilibrium than atoms in other patterns. Four groups of theorists have tried to make sense of this observation [2–6], in all cases attributing the slow thermalization to a never-before-seen effect called quantum many-body scarring.

Researchers build a quantum dot energy harvester

Over the past few years, thermoelectric generators have become the focus of a growing number of studies, due to their ability to convert waste heat into electrical energy. Quantum dots, semiconductor crystals with distinctive conductive properties, could be good candidates for thermoelectric generation, as their discrete resonant levels provide excellent energy filters.

In a recent study, researchers at the University of Cambridge, in collaboration with colleagues in Madrid, Rochester, Duisburg and Sheffield, have experimentally demonstrated the potential of an autonomous nanoscale harvester based on resonant tunneling quantum dots. This harvester is based on previous research carried out by part of their team, who had proposed a three-terminal energy harvester based on two resonant-tunneling quantum dots with different energy levels.

The energy harvester device was realized at Cavendish Laboratory in Cambridge by a researcher called Gulzat Jaliel. The original theoretical proposal for the device, however, was introduced by Andrew Jordan in 2013, and the theoretical work behind the harvester was carried out by him in collaboration with renowned semiconductor physicist Markus Büttiker and a team of post-doctoral students in Geneva.

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