论文标题
量化多体量子状态之间的差异
Quantifying the difference between many-body quantum states
论文作者
论文摘要
量子状态重叠是两个量子状态之间差异的教科书量度。但是，比较多体系统的复杂配置并不足够。该问题被广泛使用的量子状态保真度和相关距离所继承。我们介绍了加权距离，这是一类新的信息理论措施，可以克服这些限制。他们量化了区分许多粒子的两个量子状态的难度，并考虑到所需的测量设备的结构。因此，它们可用于评估复杂量子设备的理论和实验性能。我们还表明，量子过程的输入和输出状态之间的新定义的“加权布尔长度”是转换实验成本的下限。结果发现了我们将物理资源转换为计算资源的能力的确切量子限制。
The quantum state overlap is the textbook measure of the difference between two quantum states. Yet, it is inadequate to compare the complex configurations of many-body systems. The problem is inherited by the widely employed quantum state fidelity and related distances. We introduce the weighted distances, a new class of information-theoretic measures that overcome these limitations. They quantify how hard it is to discriminate between two quantum states of many particles, factoring in the structure of the required measurement apparatus. Therefore, they can be used to evaluate both the theoretical and the experimental performances of complex quantum devices. We also show that the newly defined "weighted Bures length" between the input and output states of a quantum process is a lower bound to the experimental cost of the transformation. The result uncovers an exact quantum limit to our ability to convert physical resources into computational ones.
