David Wineland, a physicist at the National Institute of Standards and Technology, won the prize Tuesday along with Frenchman Serge Haroche, a longtime friend.
The Royal Swedish Academy of Sciences cited the two scientists "for ground-breaking experimental methods that enable measuring and manipulation of individual quantum systems."
NIST spokesman Jim Burrus said Wineland was sleeping when the call came at 4 a.m. MT notifying him that he won.
His wife answered the phone. Burrus described Wineland as a humble person who never expects to win prizes.
He also doesn't seem to take himself too seriously: Wineland once played first base on a NIST softball team called "Field of Dweebs."
The two men will split the $1.2 million prize.
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