02/08/2026
IBM in collaboration with researchers from the University of Chicago has announced a major breakthrough in quantum computing by demonstrating what it describes as the first realization of verifiable quantum advantage. The achievement combines two long-standing goals in the field: performing computations beyond the practical capabilities of today's best classical simulation methods while providing strong evidence that the quantum computer's results are accurate.
The findings are detailed in the paper "Sampling Hard Circuits with Verifiably High Fidelity," which introduces a new approach to constructing encoded quantum circuits. This method enables large-scale logical quantum computations while allowing researchers to verify the fidelity of the results. The circuits and experimental data have also been made publicly available through the Quantum Advantage Tracker.
For years, researchers have relied on Random Circuit Sampling (RCS) as the standard benchmark for demonstrating quantum advantage. In an RCS experiment, a quantum computer generates highly complex output patterns that are believed to be impractical for classical computers to reproduce.
However, RCS presents a fundamental challenge: as quantum circuits become more complex, verifying the correctness of their outputs becomes increasingly difficult. Once classical computers can no longer simulate the circuit efficiently, they also lose the ability to independently confirm whether the quantum computer produced the correct answer.
To overcome this limitation, IBM and the University of Chicago developed a structured alternative to traditional RCS. Their new circuit design preserves the computational complexity required for quantum advantage while incorporating mechanisms that detect errors during ex*****on, making the results significantly easier to verify.
"Verification remains one of the biggest challenges in firmly establishing experimental quantum advantage," said Bill Fefferman, Associate Professor at the University of Chicago. "This experiment develops techniques to better characterize the fidelity of hard quantum states under noise, increasing confidence that the quantum computer is solving a computationally hard problem."
Soumik Ghosh, a PhD student in Fefferman's research group, added that advances in verification will not only strengthen experimental validation but could also help unlock practical applications for the next generation of quantum computers.
One of the Largest Logical Quantum Computing Demonstrations
The experiment represents one of the largest demonstrations of logical quantum computing to date. Researchers successfully executed computations using 70 logical qubits, performing 2,415 logical two-qubit operations and 468 logical T gates, both important measures of quantum circuit complexity.
Because the computation was protected by quantum error correction, the logical qubits experienced error rates approximately ten times lower than the underlying physical qubits. This substantial reduction enabled the system to maintain exceptionally high computational fidelity despite executing thousands of logical operations.
"We are now firmly in the quantum advantage era," said Jay Gambetta, IBM Fellow and Director of IBM Research. "We have demonstrated a quantum computation beyond the practical reach of classical computers that establishes, with statistical confidence, a lower bound on how faithfully it was executed. This milestone gives scientists, developers, and businesses a new foundation for trusting quantum computers as they scale to problems far beyond what we can achieve classically."
According to the research team, the quantum computation required approximately 15 minutes to complete on IBM's quantum hardware, while leading classical simulation methods would require prohibitively long runtimes to reproduce the same results.
Reliable error correction and confidence in computational results are widely recognized as essential milestones on the path to practical, fault-tolerant quantum computing. By combining large-scale logical quantum operations with statistically verifiable outcomes, the new demonstration represents a significant advance toward that goal.
Alongside this announcement, additional organizations within IBM's quantum ecosystem are also reporting demonstrations of quantum advantage using trusted computational methods, highlighting continued momentum across the field.
Founded in 1890, the University of Chicago is a globally recognized research institution known for advancing scholarship across science, engineering, medicine, and the humanities. Its collaborative research environment continues to produce innovations with worldwide impact.
IBM is a global technology company specializing in hybrid cloud computing, artificial intelligence, consulting, and quantum computing. Serving clients in more than 175 countries, IBM develops enterprise technologies that help organizations modernize infrastructure, improve efficiency, and accelerate digital transformation through open, secure, and scalable solutions.
SAT Reading Questions Based on the Passage
Question 1
Which choice best states the central idea of the passage?
A. IBM has developed the world's fastest quantum computer for commercial use.
B. IBM and the University of Chicago demonstrated a quantum computation that is both beyond the reach of current classical simulation methods and statistically verifiable.
C. Random Circuit Sampling is no longer useful for testing quantum computers.
D. Classical computers will soon become obsolete because of advances in quantum computing.
Question 2
According to the passage, what has been the primary limitation of Random Circuit Sampling (RCS)?
A. It requires too many logical qubits.
B. It cannot be performed on quantum computers.
C. As computations become more difficult, verifying the correctness of the results becomes infeasible.
D. It only works for classical computers.
Question 3
The word "fidelity" as used in the passage most nearly means:
A. Speed
B. Accuracy
C. Simplicity
D. Efficiency
Question 4
Why did the researchers develop encoded quantum circuits?
A. To reduce the number of physical qubits needed.
B. To make quantum computers operate more quickly.
C. To retain computational difficulty while allowing errors to be detected and results to be verified.
D. To replace logical qubits with physical qubits.
Question 5
According to the passage, why are logical qubits significant?
A. They eliminate the need for quantum gates.
B. They are protected by error correction, reducing effective error rates.
C. They are easier to simulate on classical computers.
D. They require fewer computations than physical qubits.
Question 6
Which piece of evidence best supports the claim that the experiment was conducted on a large scale?
A. The quantum computer completed the task in about 15 minutes.
B. The experiment used 70 logical qubits and performed over 2,400 logical two-qubit operations.
C. The University of Chicago was involved in the research.
D. The paper was published on the Quantum Advantage Tracker.
Question 7
The passage suggests that the researchers' new verification method primarily addresses which concern?
A. The high cost of building quantum computers
B. The difficulty of proving that quantum computers produce correct answers on extremely hard problems
C. The shortage of quantum researchers
D. The lack of commercial demand for quantum computing
Answer: B
Question 8
What can reasonably be inferred from the passage?
A. Quantum computers can now solve all practical business problems.
B. Verification techniques may help accelerate future practical applications of quantum computing.
C. Classical computers are incapable of performing scientific calculations.
D. Random Circuit Sampling has been proven incorrect.
Answer: B
Question 9
Which quotation from the passage best supports the idea that the research improves confidence in quantum computations?
A. "The University of Chicago is a leading academic and research institution..."
B. "We are now firmly in the quantum advantage era."
C. "This experiment develops techniques to better characterize the fidelity of hard quantum states under noise, increasing confidence that the quantum computer is solving a computationally hard problem."
D. "IBM is a leading provider of global hybrid cloud and AI..."
Answer: C
Question 10
The authors include the comparison between the quantum computer's runtime and classical simulation methods primarily to:
A. demonstrate that quantum computers consume less energy.
B. show that the computation performed by the quantum computer is impractical for leading classical methods.
C. prove that classical computers are no longer useful.
D. explain how logical qubits are constructed.
Answer: B
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