Continue to lead the world! Honeywell H1-2 system measures 4096 quantum volume

On April 14, Quantinuum announced that its Honeywell System Model H1-2 quantum computing system has doubled the performance, becoming the first commercial quantum computer to pass the 4096 quantum volume (QV), the quantum volume IBM announced in 2019. Launched benchmark to measure the overall capability and performance of quantum computers.

This marks the sixth time in two years that Honeywell-backed Quantinuum H-Series hardware has set an industry record for measuring quantum volume. Meanwhile, IBM announced this week that its ibm_q_prague (27-qubit processor based on the Falcon r10 series) quantum computer has boosted the IBM machine's record for the highest quantum volume from 128 to 256.

IBM Quantum Volume

Honeywell Quantum Volume

This achievement also fulfills a promise made in March 2020 by Honeywell Quantum Solutions (which merged with Cambridge Quantum to form Quantinuum in late 2021) to increase the performance of ion trap systems annually for the next five years increase by an order of magnitude. "This is the second year in a row that we have delivered on our commitment to developing the highest performing quantum hardware," said Tony Uttley, President and COO of Quantinuum.

Continuous upgrades

This week's announcement marks the second time in four months that the System Model H1-2, which went online late last year, has achieved the quantum volume milestone. The machine measured a new record quantum volume of 2048 in December 2021.

Uttley credits the doubling in performance to continuous upgrades.

Quantinuum currently operates two commercial quantum computers, H1-1 and H1-2, which run projects for customers and then upgrade them offline.

"This approach gives us the opportunity to continually add new updates and features to the system, allowing us to improve performance, we run projects to learn about our machines, and can make small upgrades or tweaks to maintain Our high fidelity."

The data
 

In tests, the average single-qubit gate fidelity was 99.994(3)%, the average two-qubit gate fidelity for fully connected qubits was 99.81(3)%, and the measurement fidelity was 99.72(5)%. Quantinuum ran 200 circuits, each executed 100 times, yielding an average of 152.97 two-qubit gates per circuit using standard QV optimization techniques.

System Model H1-2 successfully passed the benchmark test of 4096 quantum volume, returning heavy output (output whose output probability is greater than the median value of the probability set) in 69.04% of the time, which is higher than the 2/3 threshold, and the confidence level is greater than 99.99%.

The team used a new method developed by Quantinuum researchers Dr. Charlie Baldwin and Dr. Karl Mayer to calculate confidence intervals.

The graph below shows the individual heavy output probability for each circuit in the QV 4096 test. The blue line is the cumulative mean heavy output probability, and the green area is the cumulative 2σ confidence interval calculated with the new method. After executing the circuit 100 times, the heavy output probability crosses the 2/3 threshold with 2σ confidence.

The graph below shows the quantum volume growth measured by Quantinuum. For each test, the heavy output probability "h" is listed and the system is identified by the token type. The grey dotted line shows the target percentage of QV doubling 10 times per year.

What's  next?

The next step, Uttley said, is to increase the number of qubits on both quantum machines and continue to improve the fidelity of the gates.

He said: "System Model H1-2 passed the 4096 quantum volume test using all 12 fully connected qubits and we have reached the limit of 12 qubits. To continue to improve performance, we need to increase the number of qubits. Please Stay tuned for what's to come."

Link:

[1] https://www.quantinuum.com/pressrelease/quantinuum-announces-quantum-volume-4096-achievement

[2] https://research.ibm.com/blog/quantum-volume-256