Error rate continues to drop! Honeywell Sets Another World Record for 8192 Quantum Volume

 

Last week, Tony Uttley, president and COO of Quantinuum, Honeywell's quantum computing company, announced three significant achievements during his keynote address, "Measurement Methods for Quantum Computing," at the IEEE Quantum Week event in Colorado.

 

 

These three milestones, which represent an acceleration in the interoperability of the quantum computing ecosystem, are.

 

The new arbitrary angle gate (AGG) feature on the H-series hardware.

 

A new QV record for the System model H1 hardware.

 

More than 500,000 downloads of Quantinuum's open-source TKET, the world's leading quantum software development kit (SDK).

 

Quantinuum said these advances are the latest example of the company's continued demonstration of its leadership in quantum computing.

 

"Quantinuum is accelerating the impact of quantum computing on the world," said Uttley, "We have made significant progress in both hardware and software, in addition to building a community of developers using our TKET SDK. "

 

01Quantum volume breaks another record, key to new arbitrary-angle double quantum bit gate

 

The latest quantum volume (QV) measurement of 8192 is particularly noteworthy: this is the second time this year Quantinuum has published a new QV record on their trapped ion quantum computing platform (System model H1, powered by Honeywell).

 

The figure above shows the growth of the quantum volume measured by Quantinuum. For each test, the output probability 'h' is listed and the system is identified by the type of marker; the gray dashed line indicates the target ratio, which is a 10-fold increase in QV per year.

 

A key to achieving this latest record is the new ability to directly implement double quantum bit gates at arbitrary angles: for many quantum circuits, this new double quantum bit gate allows for more efficient circuit construction and leads to higher fidelity results.

 

This new capability can bring a number of advantages to users," said Dr. Brian Neyenhuis, director of commercial operations at Quantinuum. In many cases, this includes shorter interactions with quantum bits, resulting in lower error rates. This allows our customers to reduce noise when running long computations."

 

Neyenhuis says these arbitrary angle gates build on the overall design advantages of H1's trapped ion architecture.

 

With the quantum charge-coupled device (QCCD) architecture, the interactions between quantum bits are very simple: they can be limited to a small number of quantum bits," he said. This means we can precisely control the interactions without having to worry about additional crosstalk."

 

Dr. Jenni Strabley, senior director of product management at Quantinuum, said this new gate design represents Quantinuum's third approach to improving H1 efficiency.

 

"Quantinuum's goal is to accelerate quantum computing." She said, "We know we have to make the hardware better, we have to make the algorithms smarter, and we are doing that. Now we can also implement algorithms more efficiently on our H1 with this new gate design."

 

02A huge win for improving gate circuit fidelity

 

Currently, researchers can do single-quantum bit gates (rotations on a single quantum bit), or fully entangled double-quantum bit gates. Any quantum operation can be built with just these building blocks.

 

With gates of any angle, in turn, scientists can use partially entangled double quantum bit gates.

 

"There are many algorithms that can evolve the quantum state of the system one small step at a time." Neyenhuis says, "Previously, to get a tiny entanglement in some small time step, one had to entangle all the way, rotate a bit, and then unentangle almost all the way. Now, we just add this small piece of entanglement locally and then go to the next step of the algorithm."

 

According to Neyenhuis, there are other algorithms for which such arbitrarily angled double-quantum bit gates are natural building blocks. Using arbitrarily angled double quantum bit gates can cut the number of double quantum bit gates (and overall errors) in half, greatly improving the circuit's fidelity. Researchers can use this new gate design to run harder problems that have led to catastrophic errors in previous experiments, for example, the quantum Fourier transform.

 

Neyenhuis said, "By using arbitrary-angle gates, in addition to halving the number of double-quantum-bit gates, we get a much lower error per gate because it is proportional to the amplitude of that gate." This milestone has an average single-quantum bit gate fidelity of 99.9959(5)%, an average two-quantum bit gate fidelity of 99.71(3)% for fully connected quantum bits, and a state preparation and measurement fidelity of 99.72(1)%. the Quantinuum team ran 220 circuits, each with 90 shots, using standard QV optimization techniques. Each circuit produced an average of 175.2 arbitrary-angle double quantum bit gates. This is a powerful new capability, especially for noise-containing intermediate-scale quantum (NISQ) algorithms.

 

"It's a much more efficient way to run NISQ-era algorithms." There are a lot of different circuits you want to run, and this arbitrary angle of the gate gives a considerable improvement in the fidelity of the whole circuit," Neyenhuis said. This ability to also speed up the execution of the circuit by removing unneeded gates will ultimately reduce the time it takes to perform work on our machines."

 

Researchers working on machine learning algorithms, variational algorithms and time-evolving algorithms will see the greatest benefit from these new gates. This advance is particularly important for modeling the dynamics of other quantum systems.

 

Neyenhuis says, "This is a huge win for fidelity."

 

03A new milestone in quantum volume

 

Quantum volume testing requires running arbitrary circuits. In each "segment" of the quantum volume circuit, quantum bits are randomly paired and complex two-qubit operations are performed. This SU(4) gate can be built more efficiently with an arbitrary angle of the two-qubit gate, reducing the error of the algorithm at each step.

 

The top graph shows the individual re-output probabilities for each circuit in the Quantum Volume 8192 test. The blue line is the cumulative average re-output probability and the green area is the cumulative 2σ confidence interval calculated by the new method. System model H1-1 successfully passes the Quantum Volume 8192 benchmark: outputting results 69.33% of the time with a lower limit of 95% confidence interval of 68.38%, which is above the 2/3 threshold.

 

The quantum volume of 8192 for H1-1 is due in part to the implementation of arbitrary angle gates and the continued reduction in error rates. quantinuum's last quantum volume increase was in April, when the system model H1-2 doubled its performance and became the first commercial quantum computer to pass quantum volume 4096. This new increase marks the seventh time in two years that Quantinuum's H-series hardware has set an industry record for measuring quantum volume: as it continues to achieve its goal of 10x annual improvement.

 

Quantinuum Quantum Computer Roadmap

 

Quantinuum is a benchmark introduced by IBM in 2019 as a way to measure the performance of quantum computers using random circuits, and is a metric often used throughout the industry.

 

04Building a quantum ecosystem among developers

 

Quantinuum has also achieved another milestone: TKET has been downloaded more than 500,000 times.

 

TKET is an advanced software development toolkit for writing and running programs on gate-based quantum computers. TKET enables developers to optimize their quantum algorithms and reduce the computational resources required: this is very important in the NISQ era.

 

TKET is open source and can be accessed through the PyTKET Python package. The SDK also integrates with major quantum software platforms, including Qiskit, Cirq and Q#. TKET has been available as an open source language for almost a year.

 

This general availability and TKET's portability across many quantum processors is critical to building a community of developers capable of writing quantum algorithms; download users include many companies and academic institutions.

 

While we don't have the exact number of users of TKET, it's clear that we're on track for a million people worldwide," said Quantinuum CEO Ilyas Khan. They have leveraged a key tool to integrate across multiple platforms and make those platforms perform better. We continue to be excited by the way TKET is helping to democratize quantum computing and accelerate innovation."

 

The arbitrary-angle double quantum bit gate and other recent advances in Quantinuum are built into TKET.

 

"TKET is an evolving platform and continues to take advantage of these new hardware capabilities," said Dr. Ross Duncan, Quantinuum's director of quantum software, "and we are excited to put these new capabilities in the hands of the rapidly growing number of TKET users around the world. "

 

Reference link：

https://www.quantinuum.com/pressrelease/quantinuum-sets-new-record-with-highest-ever-quantum-volume