Unitary transformations can be identified locally

TL;DR

This paper demonstrates that multipartite unitary transformations can be perfectly distinguished using only local measurements and classical communication, highlighting their local distinguishability despite nonlocal characteristics.

Contribution

It proves the theoretical possibility of local discrimination of multipartite unitaries and discusses related quantum circuit constructions and extensions to general quantum operations.

Findings

Multipartite unitaries can be perfectly discriminated locally.

Construction methods for quantum circuits for discrimination.

Extension to general quantum operations discussed.

Abstract

We show that in principle, $N$-partite unitary transformations can be perfectly discriminated under local measurement and classical communication (LOCC) despite of their nonlocal properties. Based on this result, some related topics, including the construction of the appropriate quantum circuit together with the extension to general completely positive trace preserving operations, are discussed.