Advanced Control of a Six-Qubit Quantum Processor in Silicon

 Advances in silicon spin .....

Advanced Control of a Six-Qubit Quantum Processor in Silicon

By QuTech, October 7, 2022

The research shows that it's possible to increase the silicon spin qubit count while keeping the same precision as for single qubits.

Researchers at QuTech, a collaboration between the Delft University of Technology and TNO, the Netherlands Organization for Applied Scientific Research, have developed a chip with six silicon-based spin qubits that operates with a low-error rate. The research is seen as a stepping stone for the development of scalable silicon-based quantum computers.

The researchers created an array of six "quantum dots" made of individual electrons spaced 90 nanometers apart. They controlled and measured the spin of the individual electrons and facilitated their interaction using microwave radiation, magnetic fields, and electric potentials. The work is described in Nature.

"In this research we push the envelope of the number of qubits in silicon, and achieve high initialization fidelities, high readout fidelities, high single-qubit gate fidelities, and high two-qubit state fidelities," says Lieven Vandersypen, QuTech's director of research. "What really stands out though is that we demonstrate all these characteristics together in one single experiment on a record number of qubits."

From QuTech

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Quantum Datacenter Intranet Advances

 More global advances:

Quantum Datacenter Intranet Advances

By R. Colin Johnson, Commissioned by CACM Staff, April 14, 2022

U.S., European Union, and Japanese researchers recently made advances that they say are necessary for future quantum datacenters, where millions of qubits will be interconnected with a quantum intranet (the private communications grid among separate quantum computers).

In particular, this year U.S. national lab-sponsored researchers have announced the capability to preserve the coherence of quantum superposition states for five seconds, "more than 500 times longer than last year's record," according to David Awschalom, principal investigator and senior scientist at Argonne National Laboratory, director of the U.S. Department of Energy's Q-NEXT next-generation quantum research and science project, and Liew Family Professor in Molecular Engineering and Physics at the University of Chicago. During that five-second interval, as many as 100 million quantum operations and their intermediate results could be communicated over a quantum intranet, according to Awschalom.

Also this year, researchers at QuTech, a collaboration between Delft University of Technology in the Netherlands and TNO, the Netherlands Organization for applied scientific research, demonstrated quantum gates with greater than 99.5% fidelity—the benchmark accuracy needed for quantum error correction, according to Lieven Vandersypen in the QuTech lab (the achievement was confirmed independently at the Riken Center for Emergent Matter Science in Saitama, Japan). "High-fidelity control of quantum bits is paramount for the reliable execution of quantum algorithms and for achieving fault tolerance," said Vandersypen. "Having surpassed the 99% barrier for two-qubit gate fidelity, semiconductor qubits are well positioned on the path to fault tolerance."

In addition, at the end of last year, IBM announced its 127-qubit Eagle quantum computer, to be followed by its 433-qubit Osprey model later this year, and next year by a 1,121-qubit Condor model, according to IBM senior vice president Dario Gil. "Eagle, Osprey, and Condor will truly let us explore uncharted computational territory. …By 2030, we predict that our quantum computer users will be running a trillion quantum circuits per day, each of which will be solving problems that cannot be solved today on traditional digital computers."   .....  ' 

Quantum Computing Error Correction

Error correction in context  is key.

Milestone in Quantum Computing With Error Correction

By SciTechDaily, December 20, 2021

Scientists at Dutch quantum computing research institute QuTech have integrated high-fidelity operations on encoded quantum data with a scalable framework for repeated data stabilization, a key milestone in the development of quantum error correction.

The resulting logical quantum bit (qubit) features seven physical qubits or superconducting transmons.

QuTech's Jorge Marques said, "We do three types of logical-qubit operations: initializing the logical qubit in any state, transforming it with gates, and measuring it. We show that all operations can be done directly on encoded information. For each type, we observe higher performance for fault-tolerant variants over non-fault-tolerant variants."

From SciTechDaily    View Full Article

First Multi-Node Quantum Network Paves the Way for the Quantum Internet

 Though still a small number of qubits,  but the connectivity into a 'quantum internet' appears to be a big step forward.

 First Multi-Node Quantum Network Paves the Way for the Quantum Internet By ZDNet  April 16, 2021

Researchers in the Netherlands have successfully connected three separate quantum processors in what is effectively the world's first multi-node quantum network. This paves the way for a large-scale quantum internet that governments and scientists have been dreaming up for decades.

QuTech, a quantum research institute based in Delft, has published new work in which three nodes that can store and process quantum bits (also called qubits) were linked. This, according to the QuTech researchers, is the world's first rudimentary quantum network.

It would be the harbinger of an entirely new medium of calculation, harnessing the powers of subatomic particles to obliterate the barriers of time in solving incalculable problems.

Connecting quantum devices is by no means a novelty: many researchers around the world are currently working on similar networks, but so far have only succeeded in linking two quantum processors. Establishing a multi-node connection, therefore, is a key step towards significantly expanding the size of the network.

 Original article.

European Quantum Computing Facility Goes Online

 With some useful statistics about usage and capabilities.  Note integration with simulator.  Good description of use and testing processes in place.

Home/News/First European Quantum Computing Facility Goes Online/Full Text

First European Quantum Computing Facility Goes Online,  By Arnout Jaspers

Quantum Inspire, hosted by QuTech, a collaboration of Delft University of Technology and TNO, the Netherlands Organization for Applied research, consists of two independent quantum processors, Spin-2 and Starmon-5, and a quantum simulator. Anyone can create an account, use the Web interface to write a quantum algorithm, and have it executed by one of the processors in milliseconds (if there is no queue), with the result returned within a minute. The process is fully automated.  

Seen from the outside, Spin-2 and Starmon-5 are two large, cylindrical cryostats hanging from the ceiling in a university building. One floor up, a man-size stack of electronics for each takes care of the cooling, feeding the quantum processor input from users and reading out the results. Usually, there is no one in these rooms.     

The facility officially went online on April 20, and over 1,000 accounts have been created since then. Though many curious visitors never returned, active users now upload about 6,000 jobs.... "

Talk: From a Physics Experiment to a Quantum Network System

Access to the below talk is now open:

Thank you for attending Quantum Networks: From a Physics Experiment to a Quantum Network System. This webcast is now on-demand, should you like to view it again.
Use the link below to enter the webcast at any time.

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Leave your questions for the Q&A and comments now, during, and after the talk on ACM's Discourse Page at http://on.acm.org/. 

Summary
The internet has had a revolutionary impact on our world. The vision of a quantum internet is to provide fundamentally new internet technology by enabling quantum communication between any two points on Earth. Such a quantum internet can —in synergy with the “classical” internet that we have today—connect quantum information processors in order to achieve unparalleled capabilities that are provably impossible by using only classical information.

At present, such technology is under development in physics labs around the globe, but no large-scale quantum network systems exist. In this talk, we will discuss some of the efforts to move from an ad-hoc physics experiment to a scalable quantum network system. We start by providing a gentle introduction to quantum networks for computer scientists, and briefly review the state of the art. We continue to present a network stack for quantum networks, and a give an overview of a link layer protocol for producing quantum entanglement as an example.
We close by providing a series of pointers to learn more, as well as tools to download that allow play with simulated quantum networks without leaving your home.


SPEAKER
Stephanie Wehner    Delft University of Technology
Stephanie Wehner is Antoni van Leeuwenhoek Professor, and Roadmap Leader in Quantum Internet and Networked Computing at QuTech, Delft University of Technology.