Quantum physicists at UCSB’s California NanoSystems Institute have received a $6.1 million grant to pursue diamond-based quantum computing.
Research in the field could result in revolutionary breakthroughs in cryptography, communication and information processing. The grant, which was provided by the Defense Advanced Research Projects Agency and the Air Force Office of Scientific Research, will go toward research projects at CNSI and the construction of a state-of-the-art diamond synthesis facility at UCSB capable of producing perfect, single-crystal diamonds.
According to David Awschalom, director of the CNSI, diamonds exhibit many qualities that make them a useful material for constructing electronics.
“Diamond has a lot of interesting properties,” Awschalom, a professor of physics and electrical and computer engineering at UCSB, said. “It is transparent, highly conductive of heat, [acts as] a semiconductor and gives off light in the visible spectrum.”
The research goal of CNSI is to develop new, quantum-based methods for faster computing and secure communications. Due to the nature of quantum mechanics, quantum-based communication enables perfectly tamper-proof communications, Awschalom said.
One of the research projects being funded by the grant seeks to use diamond to trap electrons, in order to utilize them for quantum computing.
“The Holy Grail [of quantum computing] is to somehow trap a single electron spin as a sort of quantum bit,” Awschalom said. “But, in most materials, it is difficult to make the electron stuck in one place.”
According to Awschalom, electron-trapping requires working with materials at very low temperatures and under high pressure, which can be costly and arduous. However, in single-crystal diamonds, a carbon can be replaced by a nitrogen atom, which contains one more electron than carbon. This extra electron becomes trapped in the lattice, and its spin can be monitored at room temperature. When developed, Awschalom said, quantum-based electronics will offer far more computing power than classical electronics have to date.
The CNSI’s research may eventually lead to a diamond-based quantum processor, Awschalom said. One of the problems with current electronics is the output of excess heat, but with diamond-based electronics and quantum computing, the next generation of processors will function exponentially faster and operate at far cooler temperatures.
According to Awschalom, the diamond synthesis project may also lead to cheaper production methods of single-crystal diamonds, which may result in the eventual affordability of diamond-based electronics.
The research helmed by the CNSI is highly interdisciplinary, with scientists working in collaboration between UCSB, Harvard University, Massachusetts Institute of Technology, Hewlett-Packard Research Labs, the Lawrence Berkeley National Laboratory, the University of Iowa and the Delft University of Technology.