Experimental Activation of Bound Entanglement

TL;DR

This paper experimentally demonstrates the activation of bound entanglement in a four-qubit state, converting it into distillable entanglement using auxiliary entanglement and LOCC, potentially expanding quantum information applications.

Contribution

The first experimental activation of bound entanglement in a four-qubit state, enabling its use in quantum information processing.

Findings

Bound entanglement can be activated into distillable form.

Experimental realization using the four-qubit Smolin state.

Potential for new quantum communication applications.

Abstract

Entanglement is one of the essential resources in quantum information and communication technology (QICT). The entanglement thus far explored and applied to QICT has been pure and distillable entanglement. Yet there is another type of entanglement, called 'bound entanglement', which is not distillable by local operations and classical communication (LOCC). We demonstrate the experimental 'activation' of the bound entanglement held in the four-qubit Smolin state, unleashing its immanent entanglement in distillable form, with the help of auxiliary two-qubit entanglement and LOCC. We anticipate that it opens the way to a new class of QICT applications that utilize more general classes of entanglement than ever, including bound entanglement.