Self-testing is a method to characterise an arbitrary quantum system based only on its classical input-output correlations, and plays an important role in device-independent quantum information processing as well as quantum complexity theory. Prior works on self-testing require the assumption that the system's state is shared among multiple parties that only perform local measurements and cannot communicate. Here, we replace the setting of $\textit{multiple non-communicating}$ parties, which is difficult to enforce in practice, by a $\textit{single computationally bounded}$ party. Specifically, we construct a protocol that allows a classical verifier to robustly certify that a single computationally bounded quantum device must have prepared a Bell pair and performed single-qubit measurements on it, up to a change of basis applied to both the device's state and measurements. This means that under computational assumptions, the verifier is able to certify the presence of entanglement, a property usually closely associated with two separated subsystems, inside a single quantum device. To achieve this, we build on techniques first introduced by Brakerski et al. (2018) and Mahadev (2018) which allow a classical verifier to constrain the actions of a quantum device assuming the device does not break post-quantum cryptography.

中文翻译：

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在计算假设下对单个量子设备进行自测

自测试是一种仅基于其经典输入-输出相关性来表征任意量子系统的方法，在独立于设备的量子信息处理以及量子复杂性理论中起着重要作用。先前关于自测的工作需要假设系统的状态在多方之间共享，这些多方仅执行本地测量而无法进行通信。在这里，我们将 $\textit{multiple non-communicating}$ 方的设置替换为 $\textit{single Computingly bounded}$ 方，这在实践中很难执行。具体来说，我们构建了一个协议，允许经典验证器稳健地证明单个计算有界量子设备必须准备好一个贝尔对并对其执行单量子位测量，直到应用于设备状态和测量的基础变化。这意味着在计算假设下，验证者能够证明纠缠的存在，纠缠的存在通常与单个量子设备内的两个分离的子系统密切相关。为了实现这一点，我们以 Brakerski 等人首先引入的技术为基础。(2018) 和 Mahadev (2018) 允许经典验证器限制量子设备的行为，假设该设备不会破坏后量子密码学。