Distillability of Inseparable Quantum Systems

TL;DR

This paper demonstrates a method to distill any inseparable 2x2 quantum system using inseparability criteria, local filtering, and purification protocols, with a geometric illustration of the process.

Contribution

It extends existing distillation protocols to all inseparable 2x2 systems and provides a geometric interpretation of the process.

Findings

All inseparable 2x2 states can be distilled.

The protocol combines inseparability criteria, local filtering, and purification.

Geometric visualization aids understanding of the distillation process.

Abstract

We apply the inseparability criterion for $2 \times 2$ systems, local filtering and Bennett et al. purification protocol [Phys. Rev. Lett. {\bf 76}, 722 (1996)] to show how to distill {\it any} inseparable $2\times 2$ system. The extended protocol is illustrated geometrically by means of the state parameters in the Hilbert-Schmidt space.