Experimental Implementation of the Universal Transpose Operation

TL;DR

This paper demonstrates an optimal, experimentally feasible approximation of the universal transpose operation for qubits using linear optics, advancing quantum state manipulation techniques.

Contribution

It introduces a practical, optimal method to approximate the universal transpose of qubits and reports its successful implementation in a linear optics experiment.

Findings

Achieved maximal fidelity in the approximation

Implemented the scheme using current linear optics technology

Validated the method's practicality and optimality

Abstract

The universal transpose of quantum states is an anti-unitary transformation that is not allowed in quantum theory. In this work, we investigate approximating the universal transpose of quantum states of two-level systems (qubits) using the method known as the structural physical approximation to positive maps. We also report its experimental implementation in linear optics. The scheme is optimal in that the maximal fidelity is attained and also practical as measurement and preparation of quantum states that are experimentally feasible within current technologies are solely applied.