STOCKHOLM — A French-American duo shared the 2012 Nobel Prize in physics Tuesday for inventing methods to observe the bizarre properties of the quantum world, research that has led to the construction of extremely precise clocks and helped scientists take the first steps toward building superfast computers.

Serge Haroche of France and American David Wineland opened the door to new experiments in quantum physics by showing how to observe individual quantum particles without destroying them, the Royal Swedish Academy of Sciences said.

Haroche and Wineland, both 68, work in the field of quantum optics, which deals with the interaction between light and matter.

“Their ground-breaking methods have enabled this field of research to take the very first steps towards building a new type of superfast computer based on quantum physics,” the academy said. “The research has also led to the construction of extremely precise clocks that could become the future basis for a new standard of time.”

Through “ingenious laboratory methods,” the two scientists have managed to measure and control fragile quantum states that were previously thought to be impossible to observe directly, the judges said.

Wineland traps ions — electrically charged atoms — and measures them with light, while Haroche controls and measures photons, or light particles.

Haroche, of the College de France and Ecole Normale Superieure in Paris, said he was out walking with his wife when he got the call from the Nobel judges.

“I was in the street and passing a bench so I was able to sit down,” Haroche told a news conference in Stockholm by telephone. “It’s very overwhelming.”

Wineland is a physicist at the National Institute of Standards and Technology in Boulder, Colorado.

This year’s Nobel Prize announcements got under way Monday with the medicine prize going to stem cell pioneers John Gurdon of Britain and Japan’s Shinya Yamanaka. Each award is worth 8 million kronor, or about $1.2 million.