Measuring entanglement

Speaker: Sharmila Balamurugan

Venue : HSB 210

Date : 02nd August, 2019

Time : 5.30 p.m.

Abstract

Entanglement is an important resource in quantum information processing. Thorough experimental and theoretical investigations have been carried out on entangled systems. Nowadays, it is easy to demonstrate the generation of two qubit entanglement as ready access to quantum computers is possible. In this talk, I will use the IBM quantum computer to generate the Bell state and then proceed to describe entanglement in quantum optical systems. Entanglement dynamics reveal interesting phenomena such as entanglement sudden death, birth and collapse to a constant non-zero value. To study such effects, it is necessary to estimate the extent of entanglement as the system evolves temporally. The extent of entanglement is given by standard measures such as subsystem von Neumann entropy and subsystem linear entropy. However, to calculate such measures, we need complete information about the quantum state. In this talk, I will explain why it is not possible for experimental results to capture complete information about the state. Further, I will suggest an alternative procedure to arrive at an approximate estimate of the extent of entanglement. I will show that the proposed quantitative `indicator' of entanglement agrees reasonably well with the standard measures.

About the speaker

I am a research scholar working under the guidance of Prof. S. Lakshmibala. I work in the field of quantum dynamics. I am currently interested in quantitative signatures of nonclassical effects in optical tomograms. My non-academic interests are primarily reading novels and enjoying delicious snacks which are rich in everything that you are supposed to avoid.