Thailand’s first photograph of single atoms by quantum scientists at Chiang Mai University.
Original article in Thai by Thailand Center of Excellence in Physics (ThEP),
Translated by Phattharaporn Singkanipa, University of Cambridge,
In high school, science teachers would teach us that everything consists of atoms — but we were not able to see them because they were as tiny as 1 millionth of our hair. They are so small that finding one atom in a one-Bath-coin is as hard as finding a one-Bath-coin on the moon. For the first time in Thailand, just after this year’s National Science Week, on 10th September 2019, Chiang Mai University scientists have successfully filmed “a single Rubidium atom”.
The team consists of physicists and engineers, including Master students, Miss Jindaratsamee Phrompao and Mr. Kritsana Srakowl, as well as their supervisor, Assist. Prof. Dr. Waranont Anukool (Fig 1). Laser and their designed cooling system were used to cool Rubidium gas down to ~50 mK (100,000 times colder than the Universe’s coldest place). Over 1,000 million atoms were fed into a specially designed laser trap. Hence, only one was trapped and photographed by CCD camera. The whole process happened in less than a second, in a vacuum environment comparable to the moon’s atmosphere.
You might have expected to see something similar to some table tennis balls acting as electrons orbiting a basketball acting as a nucleus, as guided by standard textbook visualisation. However, what has been photographed was actually photon emitted from an excited Rubidium atom, which de-excited into the ground state. Its light entered CCD camera, resulting in a bright dot in Fig 2. Fig 3 shows statistics from 1,000 experiments on 15th September 2019 which proves to have only twopossibilities, 0 or 1 atom, in the light trap. Red line shows theoretical expectation.
With an atom, ~150 more photons were detected, forming the right peak. These are due to the nature of de-excitation of Rubidium atom and CCD solid angle. Being able to see a single atom is a breakthrough for Thailand and not many laboratories around the world have achieved this. This ongoing world-class competition should lie a reason behind — “Why are we doing this?”
Assist Prof Dr Woranont said “This single atom will be used as a processor and storage of quantum computer, future apparatus that would enable sci-fi fantasies to take place in real life, e.g., exponentially faster processing time would solve problems that were not solvable using current technologies, faster speed would make a huge different in money market, faster big data analysis would overcome probabilistic market condition and affect the economy system, medication would be more personalised and accurate. Moreover, quantum computer would be used in fabricating materials with interesting properties as well as setting off many more long term effects.”
The researchers hope that this leap in science would receive a huge support in order to develop more innovations, not only in quantum computer but also quantum information science and quantum sensors. This would be an important factor which adds high value to Thailand’s economy.
The researchers would like to thank Thailand Center of Excellence in Physics, National Astronomical Institute of Thailand and Synchrotron Light Research Institute for laboratory equipments, Chiang Mai University for this challenging opportunity and Mahanakorn Technology University for CCD camera which was an “eye” to “see atom”. Moreover, the team would like to thank researcher mentors, Mr. Polnop Samutpraphoot, PhD student at Harvard University, Dr. Pimonpan Sompet, a research fellow at Max Planck Institute, Germany, Rattakorn Kaewuam and Dr. Jirawat Tangpanitanon from Centre for Quantum Technologies, National University of Singapore, Singapore.
