发表机构
ETH Zurich; ENS Lyon, Inria（苏黎世联邦理工学院; 里昂高等师范学院，法国国家信息与自动化研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究线性耦合下量子门速度与脉冲能量的关系，证明固定保真度门速率最多随能量平方根增长，指出需改变相互作用类别以突破该限制。
AI 中文摘要
更快的量子门可以抑制计算过程中累积的退相干，但在超导处理器中，更强的微波脉冲也会增加泄漏、非共振激发、杂散场误差和串扰。这产生了一个核心的能量-速度-误差权衡：量子态工程能否使门在参数上更快，而无需按比例支付更多的驱动能量？我们通过将驱动脉冲视为量子玻色场而非经典波形来解决这个问题。对于与该场线性耦合的有限维系统，我们证明，在耦合和可接受动力学的给定均匀性条件下，固定保真度的门跃迁速率最多随脉冲能量的平方根增长。该界限允许任意脉冲态，包括压缩态和非高斯态，以及驱动-系统纠缠和反作用；相干高斯脉冲达到其能量指数。因此，压缩或其他态工程单独无法用一般量子速度极限所允许的线性标度取代传统线性驱动的平方根能量定律。要实现这种改进，除了使用合适的非经典脉冲外，还需要改变相互作用类别，从而将相互作用非线性确定为放松实际门速度-误差权衡的基本资源。
英文摘要
Faster quantum gates can suppress the decoherence accumulated during a computation, but in superconducting processors stronger microwave pulses can also increase leakage, off-resonant excitation, stray-field errors, and crosstalk. This creates a central energy--speed--error tradeoff: can quantum state engineering make a gate parametrically faster without paying proportionally more drive energy? We address this question by treating the driving pulse as a quantum bosonic field rather than a classical waveform. For a finite-dimensional system coupled linearly to that field, we prove that fixed-fidelity gate transition rates grow at most as the square root of the pulse energy, under stated uniformity conditions on the coupling and accepted dynamics. The bound permits arbitrary pulse states, including squeezed and non-Gaussian states, as well as drive--system entanglement and back action; coherent Gaussian pulses attain its energy exponent. Thus squeezing or other state engineering alone cannot replace the square-root energy law of a conventional linear drive by the linear scaling allowed by general quantum speed limits. Achieving that improvement requires changing the interaction class, in addition to using a suitable nonclassical pulse, thereby identifying interaction nonlinearity as an essential resource for relaxing the practical gate-speed error tradeoff.
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