Generation of arbitrary symmetric entangled states with conditional linear optical coupling

TL;DR

This paper proposes a method to generate arbitrary symmetric entangled photonic states using conditional linear optical coupling, enabling efficient production of various entangled states like N00N and coherent states.

Contribution

The paper introduces a novel protocol utilizing conditionally induced beam-splitter coupling for generating symmetric entangled states from arbitrary initial states.

Findings

Efficient generation of entangled states such as N00N and coherent states.

Implementation of the protocol via superposition of ground states.

Universal applicability to different entangled state categories.

Abstract

An approach for generating the entangled photonic states |F1,F2>+|F2,F1> from two arbitrary states |F1> and |F2> is proposed. The protocol is implemented by the conditionally induced beam-splitter coupling which leads to the selective swapping between two photonic modes. Such coupling occurs in a quantum system prepared in the superposition of two ground states with only one of them being involved in the swapping. All the entangled states in the category, such as entangled pairs of coherent states or Fock states (N00N states), can be efficiently produced in the same way by this method.