标题： 低温环境中极性分子离子的高保真量子态控制 显示英文标题

标题： High-fidelity quantum state control of a polar molecular ion in a cryogenic environment

摘要： 我们使用量子逻辑光谱（QLS）协议来控制处于低温环境中的CaH+离子的量子态，在这种环境中，减少的热辐射使旋转态寿命比室温下高出一个数量级。 通过反复且自适应地探测分子，通过原子离子检测每次探测的结果，并使用贝叶斯更新方案量化对分子态的信心，我们在单一量子态上展示了保真度小于$6\times10^{-3}$的状态准备和测量（SPAM），并测量了两个态之间的拉比振荡，对比度大于99%。 该协议不需要任何分子特异性激光，检测方案是非破坏性的。 据我们所知，这一结果代表了迄今为止演示的单个分子量子态的最高SPAM保真度。 显示英文摘要

摘要： We use a quantum-logic spectroscopy (QLS) protocol to control the quantum state of a CaH+ ion in a cryogenic environment, in which reduced thermal radiation extends rotational state lifetimes by an order of magnitude over those at room temperature. By repeatedly and adaptively probing the molecule, detecting the outcome of each probe via an atomic ion, and using a Bayesian update scheme to quantify confidence in the molecular state, we demonstrate state preparation and measurement (SPAM) in a single quantum state with infidelity less than $6\times10^{-3}$ and measure Rabi flopping between two states with greater than 99% contrast. The protocol does not require any molecule-specific lasers and the detection scheme is non-destructive. To our knowledge, this result represents the highest SPAM fidelity of a single molecular quantum state demonstrated to date.