AI 中文总结
本文提出一种基于里德伯修饰系综的平台，通过量子比特控制的集体相移实现单量子比特非破坏性探测，态赋值保真度达99.81%，为量子信息转移与接口技术提供了新方案。
AI 中文摘要
由单个量子激发携带的量子信息放大是各类量子平台中反复出现的挑战。例如，单个量子比特与介观自旋系综之间的耦合可用于实现量子比特态的非破坏性探测，但在实验中实现这类系统间的稳健耦合颇具难度，通常需要可编程量子门或天然长程相互作用。本文提出一种平台，将编码于控制原子基态-里德伯态跃迁的单量子比特，与囚禁在光学晶格中的基态原子构成的里德伯修饰目标系综耦合。研究表明，控制量子比特的态可通过量子比特控制的集体相移相干映射至该系综；对系综进行里德伯修饰后，每个目标原子的受控相移与目标原子数无关，使该方案本质上对原子数波动和原子损耗具有鲁棒性，而这正是本系统中主要的实验缺陷。利用多达8个目标自旋的集体响应，我们通过实现单个里德伯激发的非破坏性探测，以态赋值保真度$\u2139 = 99.81^{+0.17}_{-1.47}\\%$验证了该方案的有效性。本方法展示了将量子信息从单量子比特高保真度转移至介观系综的关键要素，为里德伯态的非破坏性中间电路读出及单量子比特与光子模式间的高效接口开辟了途径。
英文摘要
The amplification of quantum information carried by a single quantum excitation is a recurring challenge across diverse quantum platforms. The coupling between a single qubit and a mesoscopic ensemble of spins, for example, can be leveraged to realize non-destructive detection of the qubit state. However, realizing robust couplings between such systems is experimentally challenging and typically requires programmable quantum gates or native long-range interactions. Here, we introduce a platform that couples a single qubit, encoded in the ground-to-Rydberg transition of a control atom, to a Rydberg-dressed target ensemble of ground-state atoms trapped in an optical lattice. We show that the state of the control qubit can be coherently mapped onto the ensemble via a qubit-controlled collective phase shift. By Rydberg-dressing the ensemble, the controlled phase shift per target atom becomes independent of the number of target atoms, making the protocol intrinsically insensitive to atom-number fluctuations and atom loss, which are the dominant experimental imperfections in our system. Exploiting the collective response of up to eight target spins, we demonstrate the efficacy of the scheme by realizing non-destructive detection of a single Rydberg excitation with a state-assignment fidelity of $\mathcal{F} = 99.81^{+0.17}_{-1.47}\,\%$. Our approach demonstrates the key ingredients for high-fidelity transfer of quantum information from a single qubit to a mesoscopic ensemble, opening a route to non-destructive mid-circuit readout of Rydberg states and to efficient interfaces between single qubits and photonic modes.
Comments10 pages, 7 figures
