Lifeboat Foundation

Researchers from RIKEN and QuTech—a collaboration between TU Delft and the Netherlands Organisation for Applied Scientific Research (TNO)— have achieved a key milestone toward the development of a fault-tolerant quantum computer. They were able to demonstrate a two-qubit gate fidelity of 99.5 percent—higher than the 99 percent considered to be the threshold for building fault-tolerant computers—using electron spin qubits in silicon, which are promising for large-scale quantum computers as the nanofabrication technology for building them already exists. This study was published in Nature.

The world is currently in a race to develop large-scale quantum computers that could vastly outperform classical computers in certain areas. However, these efforts have been hindered by a number of factors, including in particular the problem of decoherence, or noise generated in the qubits. This problem becomes more serious with the number of qubits, hampering scaling up. In order to achieve a large-scale computer that could be used for useful applications, it is believed that a two-qubit gate fidelity of at least 99 percent to implement the surface code for error correction is required. This has been achieved in certain types of computers, using qubits based on superconducting circuits, trapped ions, and nitrogen-vacancy centers in diamond, but these are hard to scale up to the millions of qubits required to implement practical quantum computation with an error correction.

To address these problems, the group decided to experiment with a quantum dot structure that was nanofabricated on a strained silicon/silicon germanium quantum well substrate, using a controlled-NOT (CNOT) gate. In previous experiments, the gate fidelity was limited due to slow gate speed. To improve the gate speed, they carefully designed the device and tuned it by applying different voltages to the gate electrodes. This combined an established fast single-spin rotation technique using micromagnets with large two-qubit coupling. The result was a gate speed that was 10 times better than previous attempts. Interestingly, although it had been thought that increasing gate speed would always lead to better fidelity, they found that there was a limit beyond which increasing the speed actually made the fidelity worse.

Sandbox is the newest Quantum Computer company straight from Google which is focusing on the newly discovered Time Crystals which are posed to revolutionize computers in terms of efficiency and performance. Sandbox is separate from Google’s quantum computing team in Santa Barbara, and focuses on software and experimental quantum projects. The unit is currently led by Jack Hidary.
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TIMESTAMPS:
00:00 Google’s Newest Project.
01:07 Google’s Goal with Quantum Computers.
03:29 Google’s New Company “SandBox“
04:35 What can it be used for?
07:41 Last Words.
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#google #quantum #ai

Hardware company uses neutral atom design while algorithm experts integrate quantum algorithms into existing software platforms.

Pasqal is combining its neutral atom-based hardware with Qu&Co’s algorithm portfolio to launch a combined quantum computing company based in Paris with operations in seven countries. The companies announced the merger Tuesday, Jan. 11.

A major milestone has just been reached in quantum computing.

Three separate teams around the world have passed the 99 percent accuracy threshold for silicon-based quantum computing, placing error-free quantum operations within tantalizing grasp.

In Australia, a team led by physicist Andrea Morello of the University of New South Wales achieved 99.95 percent accuracy with one-qubit operations, and 99.37 percent for two-qubit operations in a three-qubit system.

Numbers like π, e and φ often turn up in unexpected places in science and mathematics. Pascal’s triangle and the Fibonacci sequence also seem inexplicably widespread in nature. Then there’s the Riemann zeta function, a deceptively straightforward function that has perplexed mathematicians since the 19th century. The most famous quandary, the Riemann hypothesis, is perhaps the greatest unsolved question in mathematics, with the Clay Mathematics Institute offering a $1 million prize for a correct proof.

UC Santa Barbara physicist Grant Remmen believes he has a new approach for exploring the quirks of the zeta function. He has found an analog that translates many of the function’s important properties into quantum field theory. This means that researchers can now leverage the tools from this field of physics to investigate the enigmatic and oddly ubiquitous zeta function. His work could even lead to a proof of the Riemann hypothesis. Remmen lays out his approach in the journalPhysical Review Letters.

“The Riemann zeta function is this famous and mysterious mathematical function that comes up in number theory all over the place,” said Remmen, a postdoctoral scholar at UCSB’s Kavli Institute for Theoretical Physics. “It’s been studied for over 150 years.”

| Hackaday

Quantum computers aren’t quite ready for the home lab, but since there are ways to connect to some over the Internet, you can experiment with them more easily than you might think. [Norbert] decided to interface a giant quantum computer to an ordinary Arduino. Why? Well, that isn’t necessarily clear, but then again, why not? He explains basic quantum computing and shows his setup in the video below.

Continue reading “Arduino Meets Quantum Computer” »

D-Wave Systems is ramping up in the race to so-called quantum supremacy — the bid to become the first to successfully commercialize quantum computing.

Magnets and superconductors don’t normally get along, but a new study shows that ‘magic-angle’ graphene is capable of producing both superconductivity and ferromagnetism, which could be useful in quantum computing.

When two sheets of the carbon nanomaterial graphene are stacked together at a particular angle with respect to each other, it gives rise to some fascinating physics. For instance, when this so-called “magic-angle graphene” is cooled to near absolute zero 0, it suddenly becomes a superconductor, meaning it conducts electricity with zero resistance.

Now, a research team from Brown University has found a surprising new phenomenon that can arise in magic-angle graphene. In research published in the journal Science, the team showed that by inducing a phenomenon known as spin-orbit coupling, magic-angle graphene becomes a powerful ferromagnet.

A University of Melbourne-led team has perfected a technique for embedding single atoms in a silicon wafer one-by-one. Their technology offers the potential to make quantum computers using the same methods that have given us cheap and reliable conventional devices containing billions of transistors.

“We could ‘hear’ the electronic click as each atom dropped into one of 10,000 sites in our prototype device. Our vision is to use this technique to build a very, very large-scale quantum device,” says Professor David Jamieson of The University of Melbourne, lead author of the Advanced Materials paper describing the process.

Continue reading “Building a silicon quantum computer chip atom” »