单个可信量子比特是实现极端无信号关联的必要和充分条件
Single trusted qubit is necessary and sufficient for quantum realisation of extremal no-signaling correlations
摘要：
量子统计可以从后量子无信号理论的角度来考虑，在后量子无信号理论中，没有或只有一定数量的量子系统是可信的。在这些场景中，状态的角色分别由所谓的无信令盒或无信令集合扮演。到目前为止，已经表明，在通常的贝尔非定域性场景中，只有一次测量运行，量子统计永远无法在无信号盒的集合中重现极值非定域点。我们在这里提供了一个一般的不去规则表明，后者保持真实，即使任意顺序测量是允许的。另一方面，我们证明了一个积极的结果表明，已经有一个可信的量子位是足够的量子理论产生一个自我测试的极值点内的相应的一组无信号组装。这一结果为密码协议对抗一般无信号攻击者的安全性证明提供了可能性。
英文摘要：
Quantum statistics can be considered from the perspective of postquantum no-signaling theories in which either none or only a certain number of quantum systems are trusted. In these scenarios, the role of states is played by the so-called no-signaling boxes or no-signaling assemblages respectively. It has been shown so far that in the usual Bell non-locality scenario with a single measurement run, quantum statistics can never reproduce an extremal non-local point within the set of no-signaling boxes. We provide here a general no-go rule showing that the latter stays true even if arbitrary sequential measurements are allowed. On the other hand, we prove a positive result showing that already a single trusted qubit is enough for quantum theory to produce a self-testable extremal point within the corresponding set of no-signaling assemblages. This result opens up the possibility for security proofs of cryptographic protocols against general no-signaling adversaries.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
