Sarah Kaiser is a PhD candidate from Saint Paul, Minnesota, USA. She is working to develop global-scale quantum communication with Thomas Jennewein's Quantum Photonics Laboratory. She studies at the University of Waterloo in Waterloo, Ontario.
"Kidneys are the best. They're fractals!"
Fascinated by biology and kidneys, Sarah entered Bethel University intending to pursue a career in medicine. However, Sarah's first undergraduate physics course opened her eyes to how calculus could be useful. She switched her major during her first week of class and finished her undergraduate studies with degrees in Math and Physics.
During the summers between her undergraduate classes, Sarah worked in atomic and molecular optics labs at Bethel, California Institute of Technology, and National Institute of Standards and Technology. These early research experiences piqued her interest in the elegance of quantum computing and helped to pave the way for her future work.
"Robots. Lasers. Space."
At the Institute for Quantum Computing, Sarah's research focuses on developing technology for a global quantum communications network. Current fiber-based commercial quantum cryptographic devices are limited to distances of a few hundred kilometers. Sarah and her colleagues are working to extend the range of these devices to span the globe by using low-Earth-orbit satellites as network nodes.
As part of this work, she collaborated with the Canadian Space Agency and space industry partners to improve photon detectors, which are key components of a global quantum network. Current avalanche photodiodes are not made for the rigours of space travel; they only survive for a few weeks after being launched into space before being destroyed by high-energy radiation. Sarah and other IQC researchers have developed a way to reverse this damage in flight so the detectors can survive a 2-year mission in space on board a satellite.
"I'm wilfully violating the warranty!"
But not all of Sarah's work is space-bound. One of her projects explored the security of commercial quantum cryptographic systems. In 2013, she and colleagues hacked the physical implementation of an ID Quantique quantum key distribution device used by governments and banks, and suggested countermeasures. This exciting work will help to strengthen the security of future cryptosystems and develop a robust quantum cryptography community.
When she's not hacking cryptosystems and designing space technology, Sarah is an avid scuba diver and lover of the ocean, an active organizer for women in science and technology fields, and a community builder. In 2015, she was awarded the IQC David Johnston Award for Scientific Outreach for her efforts. After she completes her graduate degree, Sarah is planning to pursue an international career in quantum cryptography. She hopes that CryptoWorks21 will help her gain a perspective on information and communication industries in Canada and abroad.
 J.-P. Bourgoin, B. L. Higgins, N. Gigov, C. Holloway, C. J. Pugh, S. Kaiser, M. Cranmer, and T. Jennewein, "Free-space quantum key distribution to a moving receiver," Opt. Express 23, 33437-33447 (2015). V. Makarov, J.-P. Bourgoin, P. Chaiwongkhot, M. Gagne, T. Jennewein, S. Kaiser, R. Kashyap, M. Legre, C. Minshull, S. Sajeed, “Laser damage creates backdoors in quantum communications,” arXiv:1510.03148 [quant-ph] (2015).