View article

In this chapter, we discuss the phenomena of quantum entanglement within the framework of quantum resource theories. In particular, we study entanglement witnesses and their properties. This chapter incorporates two main results on the theory of entanglement, namely, ultrafine entanglement witnessing and measurement-device-independent quantification of entanglement. The first result presents a new approach for improving standard witnessing techniques by using additional information obtained within witnessing experiments and thus, cope with unexpected experimental imperfections. The second result illustrates the use of entanglement witnessing in construction of measures of entanglement that are independent of the specific description of measurement devices similar to a Bell scenario.