We investigate the bound on the speed of state transformation in the quantum systems that are coupled to general environments. We focus on the energy fluctuation of the target system and the coupling to the environment, and clarify the universal constraint on the state transformation deriving the general speed-limit inequality. This speed-limit inequality is applicable to any open systems including physical situations that have not been studied so far. We apply the inequality to the thermalization phenomena in isolated quantum systems, and the quantum cyclic engines. For the thermalization, we provide several inequalities to estimate the equilibration time. In the cyclic heat engines, we derive a rigorous constraint on the state change in the cycle where the Planck constant plays a fundamental role.

中文翻译：

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与一般环境耦合的开放系统的速度限制

我们研究耦合到一般环境的量子系统中状态转换速度的界限。我们着眼于目标系统的能量波动以及与环境的耦合，并阐明了导致一般限速不等式的状态转换的普遍约束。这种限速不等式适用于任何开放系统，包括到目前为止尚未研究的物理情况。我们将不等式应用于孤立量子系统和量子循环引擎中的热化现象。对于热化，我们提供了几个不等式来估计平衡时间。在循环热机中，我们对循环中的状态变化施加了严格的约束，其中普朗克常数起着根本性的作用。