Original title: Frequency-Multiplexed Parallel Gates for Quantum LDPC Codes in a Two-Dimensional Ion Crystal
G. -X. Tang, L. -M. Duan, Y. -K. Wu · September 2026
Quantum computers need error-correction codes to protect information. Some efficient options, called quantum low-density parity-check codes, require distant qubits—the basic units of quantum data—to connect with each other. Moving trapped ions to make these connections physically slows down as systems grow larger. To fix this, researchers designed a way to perform parallel operations on distant ions held in a stationary two-dimensional crystal. Instead of moving them, they use frequency-multiplexingControlling multiple quantum gates simultaneously by assigning them different frequency bands., which sends different light frequencies to drive multiple gates at once. Keeping the operations adiabatic suppresses crosstalk errors, gate infidelity, and slow drifts in trap frequency. Tests on a simulated crystal of 512 ions show this method needs only moderate laser power and reaches an exceptionally low logical error rate of $10^{-12}$.
When a large group needs to coordinate from different spots, physically moving everyone to each position takes time and creates confusion. If the group grows, this slowdown becomes a major problem. In this paper, quantum operations across a fixed crystal are coordinated using different 'frequency bands' instead of moving qubits, allowing multiple actions to happen at once without the delay of physical rearrangement.
Physical qubit movement slows down quantum computers as they scale. This method lets error-correcting gates run in parallel without movement, making larger quantum systems faster and more practical.
The abstract presents a numerical example, so experimental validation is not provided. The work focuses on a specific quantum code and ion crystal setup, which may not generalize to all quantum computing platforms.
Ask anything about this paper. Answers come from its abstract, and say so when the abstract doesn't cover your question.
Frequency-Multiplexed Parallel Gates for Quantum LDPC Codes in a Two-Dimensional Ion Crystal — G. -X. Tang, L. -M. Duan, Y. -K. Wu
Abstract licence: CC0
Explanation generated by Synthesis from the abstract — it is not the original paper. This is a preprint, so it hasn't necessarily been peer reviewed.