I. Šupić (Univ. of Geneve): Device-independent certification of tensor products of quantum states
Channel: Centrum Fizyki Teoretycznej PAN
Date: 2021-04-24

Ivan Šupić (University of Geneve)
Device-independent certification of tensor products of quantum states using single-copy self-testing protocols.
Self-testing protocols are methods to determine the presence of shared entangled states in a device independent scenario, where no assumptions on the measurements involved in the protocol are made. A particular type of self-testing protocol, called parallel self-testing, can certify the presence of copies of a state, however such protocols typically suffer from the problem of requiring a number of measurements that increases with respect to the number of copies one aims to certify. Here we propose a procedure to transform single-copy self-testing protocols into a procedure that certifies the tensor product of an arbitrary number of (not necessarily equal) quantum states, without increasing the number of parties or measurement choices. Moreover, we prove that self-testing protocols that certify a state and rank-one measurements can always be parallelized to certify many copies of the state. Our results have immediate applications for unbounded randomness expansion. 
CTP Quantum Information Days (online), 22-24 February 2021.
Center for Theoretical Physics PAS (Warsaw, Poland)