The prime factors of the number 15 are 3 and 5. Easy, right? Yes, but try figuring out the prime factors of a 600-digit number. Who has age-of-the-universe time to solve that? A group of UCSB researchers has designed and built a quantum processor that can factor a composite number.
In the UCSB experiments, the number 15 was used, and the processor factored it into its prime factors of 3 and 5. While this may seem like a minor project, it’s an achievement that takes a strong step forward in the longer-term quest to create a quantum computer that can factor much larger numbers. This work would have significant implications for the fields of cryptography and cybersecurity.
The work is published online in the journal Nature Physics, and its lead author is Erik Lucero, a Ph.D. student in Physics at the time the research was done and the paper was written. He received his Ph.D. in June 2012 and since May he has worked at IBM as a postdoctoral researcher in the experimental quantum computing effort at the T.J. Watson Research Center in Yorktown Heights, N.Y.
"Fifteen is a small number, but what's important is we've shown that we can run a version of Peter Shor's prime factoring algorithm on a solid state quantum processor. This is really exciting and has never been done before," Erik said in a UCSB Office of Public Affairs press release. See the video below to get a closer look at his research.
Since the concepts used are the same when factoring much larger numbers, "we just need to scale up the size of this processor to something much larger,” Andrew Cleland, a professor of physics at UCSB who also worked on the experiment, said in the release. “This won't be easy, but the path forward is clear."
“A quantum computer will be a game changer in a lot of ways, and certainly with respect to computer security,” Erik said in the release.
Erik himself is one of those game changers. He told the GradPost what this achievement means to him.
“Since I am the first in my family to complete a Ph.D., I have dedicated my thesis to my family,” he told us. “I feel like I have blazed a trail for the Luceros in the world and I couldn't have done it without the everlasting support of my family through the years. Of course, these accomplishments are still soaking in, but I can say that I sleep a lot better now that I have defended and my thesis work is published in Nature Physics.”
For Erik, there’s a certain prestige in having worked on research at UCSB. “Certainly in the field that I am working in, Quantum Computing, the scientific research conducted at UC Santa Barbara is among the best in the world. Heads turn when I tell people where I completed my Ph.D. I am proud to have made a contribution to human knowledge and to have furthered the already great reputation of UC Santa Barbara.”
Other UCSB researchers participating in the study include John Martinis, professor of physics; Professor Cleland; Rami Barends, Yu Chen, Matteo Mariantoni, and Y. Yin, postdoctoral fellows in physics; and physics graduate students Julian Kelly, Anthony Megrant, Peter O'Malley, Daniel Sank, Amit Vainsencher, Jim Wenner, and Ted White.
For more information, read the full Office of Public Affairs press release and the Nature Physics article. For more information on how to give to graduate education initiatives that include research fellowships, visit the Graduate Division’s Giving page.