Computer Science · Artificial Intelligence
Researchers report that silicon spin qubits can perform precise operations in parallel, overcoming a major source of error during simultaneous control. In a five-qubit array, gate fidelities stayed above 99.99% for up to three qubits and above 99.9% when all five operated together.
A study proposes encoding each quantum bit into several physical qubits before measurement, then using a majority vote to decode the result. Simulations based on noise profiles from superconducting quantum platforms found that the approach suppressed measurement errors by several orders of magnitude with a modest linear increase in qubit use.
Researchers developed a quantum method for the maximum cut problem and proved a stronger worst-case guarantee than a three-round version of a widely used approach. On IBM quantum devices with 72 and 148 qubits, the method exceeded a known classical hardness threshold, while the comparison method did not do so in the 148-qubit test.
Researchers present a modular algorithm for preparing general mixed quantum states on quantum computers. Tests covered two-qubit examples and random states involving one, two and three qubits, but the abstract does not report performance measures or scaling limits.
