Enlarge (credit: IBM )

Today, IBM announced the latest generation of its family of avian-themed quantum processors, the Osprey. With more than three times the qubit count of its previous-generation Eagle processor, Osprey is the first to offer more than 400 qubits, which indicates the company remains on track to release the first 1,000-qubit processor next year.

Despite the high qubit count, there's no need to rush out and re-encrypt all your sensitive data just yet. While the error rates of IBM's qubits have steadily improved, they've still not reached the point where all 433 qubits in Osprey can be used in a single algorithm without a very high probability of an error. For now, IBM is emphasizing that Osprey is an indication that the company can stick to its aggressive road map for quantum computing, and that the work needed to make it useful is in progress.

On the road

To understand IBM's announcement, it helps to understand the quantum computing market as a whole. There are now a lot of companies in the quantum computing market, from startups to large, established companies like IBM, Google, and Intel. They've bet on a variety of technologies, from trapped atoms to spare electrons to superconducting loops. Pretty much all of them agree that to reach quantum computing's full potential, we need to get to where qubit counts are in the tens of thousands, and error rates on each individual qubit are low enough that these can be linked together into a smaller number of error-correcting qubits.

Enlarge (credit: Aurich Lawson / Getty Images)

Inspired by the functioning of pulsed lasers, scientists from France and Japan have developed an acoustic counterpart that enables the precise and controlled transmission of single electrons between quantum nodes.

Riding the waves

The spin of an electron can serve as a basis for creating qubits—the basic unit of information of quantum computing. In order to process or store that information, the information in qubits may have to be transported between quantum nodes in a network.

One option is transporting the electrons themselves, something that can now be done by having them ride sound waves. “More than 10 years ago, we demonstrated it for the first time,” said lead researcher Christopher Bauerle of the Grenoble-based Institute Néel .

Enlarge (credit: Getty Images)

In the US government's ongoing campaign to protect data in the age of quantum computers, a new and powerful attack that used a single traditional computer to completely break a fourth-round candidate highlights the risks involved in standardizing the next generation of encryption algorithms.

Last month, the US Department of Commerce's National Institute of Standards and Technology, or NIST, selected four post-quantum computing encryption algorithms to replace algorithms like RSA, Diffie-Hellman, and elliptic curve Diffie-Hellman, which are unable to withstand attacks from a quantum computer.

In the same move, NIST advanced four additional algorithms as potential replacements pending further testing in hopes one or more of them may also be suitable encryption alternatives in a post-quantum world. The new attack breaks SIKE, which is one of the latter four additional algorithms. The attack has no impact on the four PQC algorithms selected by NIST as approved standards, all of which rely on completely different mathematical techniques than SIKE.

Enlarge / An ion trap, the quantum hardware that was used for this work. (credit: Honeywell )

You can almost hear the indrawn breath from newsrooms around the world. Specialist science journalists have hidden themselves in the bathroom to weep quietly. The cause of such despair? Someone has released a paper containing the word "topology"—something no one knows how to explain, which forces people to resort to metaphors about donuts being forced to become coffee cups, despite there being neither coffee nor donuts on offer.

And although topology is fundamental to the new results, it is also tangential to explaining them (in my view, anyway). So what are those results?

One of the big problems with quantum computers is that they accumulate errors, and the speed at which that happens limits the complexity of the problems they can solve. This new paper shows how to reduce errors, not by engineering but by understanding (and using) the right quantum states and their coupling to generate a system that is naturally more immune to certain types of noise. So grab a coffee and a donut, and let's dive into the noisy world of qubits.

Enlarge / Conceptual computer artwork of electronic circuitry with blue and red light passing through it, representing how data may be controlled and stored in a quantum computer. (credit: Getty Images)

In the not-too-distant future—as little as a decade, perhaps, nobody knows exactly how long—the cryptography protecting your bank transactions, chat messages, and medical records from prying eyes is going to break spectacularly with the advent of quantum computing. On Tuesday, a US government agency named four replacement encryption schemes to head off this cryptopocalypse.

Some of the most widely used public-key encryption systems—including those using the RSA, Diffie-Hellman, and elliptic curve Diffie-Hellman algorithms—rely on mathematics to protect sensitive data. These mathematical problems include (1) factoring a key's large composite number (usually denoted as N) to derive its two factors (usually denoted as P and Q) and (2) computing the discrete logarithm that keys are based on.

The security of these cryptosystems depends entirely on classical computers' difficulty in solving these problems. While it's easy to generate keys that can encrypt and decrypt data at will, it's impossible from a practical standpoint for an adversary to calculate the numbers that make them work.

Enlarge / Google's Sycamore processor. (credit: Google )

People have performed many mathematical proofs to show that a quantum computer will vastly outperform traditional computers on a number of algorithms. But the quantum computers we have now are error-prone and don't have enough qubits to allow for error correction. The only demonstrations we've had involve quantum computing hardware evolving out of a random configuration and traditional computers failing to simulate their normal behavior. Useful calculations are an exercise for the future.

But a new paper from Google's quantum computing group has now moved beyond these sorts of demonstrations and used a quantum computer as part of a system that can help us understand quantum systems in general, rather than the quantum computer. And they show that, even on today's error-prone hardware, the system can outperform classical computers on the same problem.

Probing quantum systems

To understand what the new work involves, it helps to step back and think about how we typically understand quantum systems. Since the behavior of these systems is probabilistic, we typically need to measure them repeatedly. The results of these measurements are then imported into a classical computer, which processes them to generate a statistical understanding of the system's behavior. With a quantum computer, by contrast, it can be possible to mirror a quantum state using the qubits themselves, reproduce it as often as needed, and manipulate it as necessary. This method has the potential to provide a route to a more direct understanding of the quantum system at issue.

Enlarge / Given an actual beam of light, a beamsplitter divides it in two. Given individual photons, the behavior becomes more complicated. (credit: Wikipedia )

Ars Technica's Chris Lee has spent a good portion of his adult life playing with lasers, so he's a big fan of photon-based quantum computing. Even as various forms of physical hardware like superconducting wires and trapped ions made progress, it was possible to find him gushing about an optical quantum computer put together by a Canadian startup called Xanadu. But, in the year since Xanadu described its hardware, companies using that other technology continued to make progress by cutting down error rates , exploring new technologies , and upping the qubit count .

But the advantage of optical quantum computing didn't go away, and now Xanadu is back with a reminder that it hasn't gone away either. Thanks to some tweaks to the design it described a year ago, Xanadu is now able to sometimes perform operations with more than 200 qubits. And it's shown that simulating the behavior of just one of those operations on a supercomputer would take 9,000 years, while its optical quantum computer can do them in just a few dozen milliseconds.

This is an entirely contrived benchmark: just as Google's quantum computer did , the quantum computer is just being itself while the supercomputer is trying to simulate it. The news here is more about the potential of Xanadu's hardware to scale.