Realizing Physical Approximation of the Partial Transpose

TL;DR

This paper introduces a practical, basis-independent scheme for approximating the partial transpose of quantum states using local measurements and classical communication, demonstrated through linear optical implementation for entanglement detection.

Contribution

It presents a novel, basis-independent method to physically approximate the partial transpose, enabling practical entanglement detection in quantum systems.

Findings

Successful linear optical realization of the scheme

Effective entanglement detection demonstrated

No dependence on local basis of quantum states

Abstract

The partial transpose by which a subsystem's quantum state is solely transposed is of unique importance in quantum information processing from both fundamental and practical point of view. In this work, we present a practical scheme to realize a physical approximation to the partial transpose using local measurements on individual quantum systems and classical communication. We then report its linear optical realization and show that the scheme works with no dependence on local basis of given quantum states. A proof-of-principle demonstration of entanglement detection using the physical approximation of the partial transpose is also reported.