Dr Yaseera Ismail in the laboratory.

An article on quantum entanglement in the Journal of Optical Society of America B by post-doctoral Fellow at UKZN’s Centre for Quantum Technology, Dr Yaseera Ismail, was selected as the editor’s pick.

The editor selects articles of excellent scientific quality representing work taking place in a specific field.

The article, titled “Instrumentation Limitation on a Polarisation-based Entangled Photon Source”, deals with quantum effects in information science, specifically the hindering of optical communication by atmospheric turbulence that disperses the optical beam. Ismail and her colleagues mimicked the effects of turbulence on entangled photons in a laboratory.

Ismail explained that the study fell under Quantum Key Distribution (QKD), an application of quantum information science that aims to enhance the security of information by a physical process of transferring information from point to point by means of quantum carriers, or more precisely, single photons.

‘Quantum entanglement occurs when a pair of sub-atomic particles, such as photons, interact resulting in an invisible connection shared between them. This connection exists irrespective of the distance between the particles, and a change in one of the particles instantaneously affects the corresponding connected particle, even when separated by great distances.’

Ismail and colleagues measured the entanglement of photons and demonstrated that the overall coupling inefficiency can be corrected by the use of a multimode fibre, suggesting that care is required when choosing a detection system for free-space quantum communication systems.

The phenomenon of quantum entanglement – one of quantum physics’ ‘weirdest’ phenomena. according to Ismail – presented a challenge to her to be able to build a single photon source and prove the existence of quantum entanglement, a considerable accomplishment for the emerging researcher. She began work on this research in 2015 while working on her PhD, and built the first single photon source at UKZN.

UKZN and the University of the Witwatersrand are the only two universities in South Africa working on the experimental development of quantum entanglement focusing on advancement of quantum encryption techniques. UKZN’s quantum research group has an active experimental group comprising post-doctoral fellows, masters and PhD students.  They built the first single photon source in Africa to be commercially available, and are working on other prototypes and numerous projects related to quantum communication.

Having her work recognised by the editor gave Ismail considerable encouragement to continue to pursue her scientific goals. She hopes to continue her academic career to the level of Professor.

Words by: Christine Cuénod

Photograph: supplied by Centre for Quantum Technology