Friday, February 16, 2024

11:00 - 12:00

Self-testing allows a classical verifier to infer a quantum mechanical description of untrusted quantum devices that she interacts with in a black-box manner. Somewhat contrary to the black-box paradigm, existing self-testing results tend to presuppose conditions that constrain the operation of the untrusted devices. A common assumption is that these devices perform a projective measurement of a pure quantum state. Naturally, in the absence of any prior knowledge it would be appropriate to model these devices as measuring a mixed state using POVM measurements, since the purifying/dilating spaces could be held by the environment or an adversary.

We prove a general theorem allowing to remove these assumptions, thereby promoting most existing self-testing results to their assumption-free variants. On the other hand, we pin-point situations where assumptions cannot be lifted without loss of generality. As a key (counter)example we identify a quantum correlation which is a self-test only if certain assumptions are made. Remarkably, this is also the first example of a correlation that cannot be implemented using projective measurements on a bipartite state of full Schmidt rank.

QuSoft

UvA - Faculty of Science

L016 OR ZOOM: https://eur04.safelinks.protection.outlook.com/?url=httpscwi-nl.zoom.usj87199479914pwdWGk2K3pCc0ZnUnFjTlJOREIrU3hZZz09&data=0502J.vanMamerenuva.nl0d5ce28c9eb044aff07708dc2b476b0da0f1cacd618c4403b94576fb3d6874e500638432832949548525UnknownTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn00&sdata=mEyu5BWmpfMQuGFKdpkiqEfgJuCJ7rhZWM3lCeeEvAE&reserved=0

Group Seminar

quantum computing, quantum gases and quantum information, quantum matter

Ranyiliu Chen (University of Copenhagen)