Timothy Proctor, Kenneth Rudinger, Kevin Young, Erik Nielsen, Robin Blume-Kohout
备注：
4 pages + appendices. Please see the published paper for the final version of this work. The version here does not contain changes implemented in the peer-review process. Data and code for this manuscript can be found at https://zenodo.org/record/5197499
A quantum computer has now solved a specialized problem believed to be intractable for supercomputers, suggesting that quantum processors may soon outperform supercomputers on scientifically important problems. But flaws in each quantum processor limit its capability by causing errors in quantum programs, and it is currently difficult to predict what programs a particular processor can successfully run. We introduce techniques that can efficiently test the capabilities of any programmable quantum computer, and we apply them to twelve processors. Our experiments show that current hardware suffers complex errors that cause structured programs to fail up to an order of magnitude earlier - as measured by program size - than disordered ones. As a result, standard error metrics inferred from random disordered program behavior do not accurately predict performance of useful programs. Our methods provide efficient, reliable, and scalable benchmarks that can be targeted to predict quantum computer performance on real-world problems.
Composable security of measuring-Alice blind quantum computation
盲量子计算[A. Broadbent、J. Fitzsimons和E. Kashefi，Proceedings of the 50 th Annual IEEE Symposium on Foundations of Computer Science 517（2009）]是一种安全的云量子计算协议，其使得客户端（其没有足够的量子技术供其支配）能够将其量子计算委托给服务器（其具有通用量子计算机），而不向服务器泄露任何相关信息。在[T. Morimae和K. Fujii，Phys.Rev.A { \bf 87}，050301（R）（2013）]，提出了一种新的盲量子计算协议，所谓的测量-Alice协议。该协议提供了几个优点，比以前的协议，如设备无关的安全性，客户端的要求较低，和一个更简单，更强大的安全性的基础上无信令的原则。本文利用构造密码学[U。Maurer，Proceedings of Theory of Security and Applications，TOSCA 2011，第33-56页。Springer（2011）]。度量Alice协议的上述优点使得组合安全性的证明更加直观和透明。
Measuring out-of-time-order correlators on a quantum computer based on an irreversibility-susceptibility method
Graduate School of Information Science and Technology, Hokkaido University（北海道大学信息科学技术研究院）；RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS), RIKEN（理化学研究所跨学科理论与数学科学中心（iTHEMS））；Department of Informatics, Faculty of Information Science and Electrical Engineering, Kyushu University（九州大学信息科学与工程学部信息系）；JST, FOREST（日本科学技术振兴机构，前沿研究项目）
