Device-independent certification of tensor products of quantum states using single-copy self-testing protocols

Device-independent certification of tensor products of quantum states using single-copy self-testing protocols

Blog Article

Self-testing protocols are methods to determine the presence of shared entangled states in a Scales 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 Construction 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 suggest a method to achieve device-independent unbounded randomness expansion with high-dimensional quantum states.