"Fighting the decoherence time is the largest problem," he said. "For other problems there are some solutions and lots of possibilities but the decoherence is more difficult."
"The decoherence time (observed in the experiment) is rather short," he said. "We didn't optimize it so its roughly a few hundred picoseconds. (A picosecond is a trillionth of a second) A CNOT time pulse is about 15 picoseconds so within that time we can do a few operations, maybe two or something."
Despite the hurdles, Tsai's research is going well, said Eiichi Maruyama, director of the Frontier Research System at RIKEN. He said its still hard to estimate when a viable quantum computer might be developed however. "Our guess is anywhere between 10 years and 100 years from now," he said.
Full details of Tsai's experiment are included in the Oct. 30 edition of the British scientific journal Nature.