Chinese team breaks quantum computing's speed-fidelity trade-off

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A Chinese research team has broken a genuinely long standing bottleneck in superconducting quantum computing, finding a way to keep two qubit gates fast without sacrificing accuracy, something the field has struggled with for years given how these two properties usually trade off against each other

The team, jointly formed by Origin Quantum and the University of Science and Technology of China, proposed a scheme called the parameter space expansion controlled Z gate, or PSE-CZ for short, the work has been published in the well regarded journal Physical Review Letters, with experiments actually carried out on Chinas self developed superconducting quantum computer Origin Wukong rather than staying purely theoretical

The core problem this addresses is genuinely fundamental to how quantum gates work, faster gates tend to worsen waveform distortion and timing errors, which hurts precision, while slower operations that preserve accuracy drag down overall system performance, thats been a persistent trade off that quantum hardware engineers have had to navigate around rather than actually solve, forcing compromises in basically every superconducting quantum processor design

To test the new scheme, the team ran PSE-CZ across 20 pairs of two qubit gates on Origin Wukong, the results showed the approach genuinely suppresses errors caused by short time distortion, pushing gate performance closer to whats called the dephasing limit, essentially the theoretical ceiling for how accurate a gate can be given the physical qubits natural decoherence properties, even at extremely short gate times of just 30 to 40 nanoseconds, PSE-CZ still outperformed conventional CZ gates that have been the standard approach

Whats genuinely notable is the scheme isnt limited to superconducting systems specifically, the underlying approach could extend to other quantum computing platforms including ion traps and solid state spin qubits, which suggests this could end up being a genuinely broadly applicable technique rather than just a superconducting specific fix, promising faster and higher fidelity quantum logic operations across multiple different hardware approaches simultaneously if it translates well

Chinese team cracks quantum computing speed-fidelity trade-offnews.cgtn.com