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Tuesday, 30 October 2018

Breakthrough for quantum physics group

PROGRESS: Dr Kessie Govender and doctoral candidate Adrian Wyngaard. PROGRESS: Dr Kessie Govender and doctoral candidate Adrian Wyngaard. Theresa Smith

The Western Cape may have experienced a heat wave in October, but CPUT’s Bellville campus underwent a cold spell.

Physicist Dr Kessie Govender, leader of the CPUT Quantum Physics Research Group, succeeded in cooling a cloud of rubidium atoms to around 17 micro Kelvins, which is approximately -273 degrees Celsius below zero. The research group managed to obtain an approximately 3mm square cloud of cold Rubidium 87 atoms at around noon on Thursday 4 October 2018.

The group currently includes doctoral students Adrian Wyngaard and Rory Pentz, and masters student Victory Opeolu, all of whom are actively involved in this project.

“We are one of a few groups to achieve this in South Africa and possibly Africa. The other research group that claims to have cold atoms is the group at UKZN, however no reported measurements of the temperature or cloud parameters have been published by them as far I know,” said Govender about this first step in developing components for quantum computing locally.

Govender started the Quantum Physics Research Group in 2015 to investigate laser cooling of atoms and the development of quantum information processing components.

“There are many platforms for doing quantum computing and we’ve chosen one particular platform where we use lasers to cool down atoms. You can do a lot of things with cold atoms. For example, you can make atomic clocks, which is something I want to do because we work closely with the satellite programme on campus, F’SATI.”

“The idea is to shrink it down to be used in the nano-satellite. Data is sent from one satellite to the next but all the data needs to be tagged with a time stamp. While everything does have a margin of error, the atomic clock’s margin of error is a lot smaller than any other kind.”

Govender is pleased that he has gotten this far with his research based on a set-up that the research group assembled themselves.

Over the past three years the Quantum Physics Research Group has built and grown their own electronic set-up, spending the last six months optimising the system’s parameters. The system, positioned on two optical tables, consists of a saturated spectroscopy set-up to control the cooling and re-pumping lasers plus a vacuum chamber where the atoms are cooled. The vacuum chamber is an octagonal chamber, from Kimball Physics, with a large view port in front and a number of small view ports on the sides.

Next they have to think about how to expand the system as they continue their experiments.

“We still need to characterise the cloud and do experiments on them, move them into little traps. Then we have to move on to creating a Bose-Einstein Condensate,” he said.

Written by Theresa Smith

Email: smitht@cput.ac.za

Provides coverage for the Applied Sciences and Engineering Faculties and the Wellington Campus.