Chinese researchers have created a quantum processing unit (QPU) that outperforms the world’s best supercomputers by a factor of 1 quadrillion (10¹⁵).
Their latest prototype, the 105-qubit “Zuchongzhi 3.0,” utilizes superconducting qubits and marks a major advancement in quantum computing, according to scientists at the University of Science and Technology of China (USTC) in Hefei.
The chip competes with Google’s Willow QPU, unveiled in December 2024, which demonstrated quantum supremacy—the point at which quantum computers surpass classical supercomputers in performance, livescience.com reported.
In a study published on March 3 in Physical Review Letters, the researchers revealed that their processor completed a widely used quantum computing benchmark, random circuit sampling (RCS), in just a few hundred seconds. The test, which involved an 83-qubit, 32-layer random circuit sampling task, was executed 1 million times faster than Google’s previous-generation Sycamore chip. In contrast, Frontier, the world’s second-fastest supercomputer, would require 5.9 billion years to complete the same task.
While these findings highlight the potential of QPUs to achieve quantum supremacy, the RCS benchmark inherently favors quantum computing. Additionally, advancements in classical computing algorithms may narrow the gap, as seen in 2019 when Google’s initial claim of quantum supremacy was later challenged by improved classical methods.
Zuchongzhi 3.0 features 105 transmon qubits arranged in a 15-by-7 grid. These qubits, made from metals like tantalum, niobium, and aluminum, are designed for reduced sensitivity to noise. This is an upgrade from its predecessor, which contained 66 qubits.
A key factor in quantum computing’s real-world application is coherence time—the duration a qubit can maintain its superposition to perform parallel calculations. Longer coherence times enable more complex computations.
Other improvements include gate fidelity and quantum error correction, crucial for building practical quantum computers. Gate fidelity measures the accuracy of quantum gates, which function similarly to classical logic gates but manipulate qubits in a quantum state. Higher fidelity translates to fewer errors and more precise computations.
Zuchongzhi 3.0 achieved a parallel single-qubit gate fidelity of 99.90% and a parallel two-qubit gate fidelity of 99.62%, closely rivaling Google’s Willow QPU, which reached 99.97% and 99.86%, respectively.
These advancements were made possible through engineering refinements, such as improved fabrication techniques and optimized qubit designs. The latest version of the chip employs a lithographically defined qubit structure, using tantalum and aluminum bonded via an indium bump flip-chip process, enhancing accuracy and reducing contamination.
The researchers believe their work represents a step toward a future where quantum processors tackle complex real-world problems.
