A French-American duo shared the 2012 Nobel Prize in physics on 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.

Frenchman Serge Haroche and American David Wineland (both 68) opened the door to new experiments in quantum physics by showing how to observe individual quantum particles while preserving their quantum properties.

A quantum particle is one that is isolated from everything else. In this situation, an atom or electron or photon takes on strange properties. It can be in two places at once, for example. It behaves in some ways like a wave. But these properties are instantly changed when it interacts with something else, such as when somebody observes it.

Working separately, the two scientists developed “ingenious laboratory methods” that allowed them to manage and measure and control fragile quantum states, said the Royal Swedish Academy of Sciences. “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,” said the academy. “The research has also led to the construction of extremely precise clocks that could become the future basis for a new standard of time.”

The two researchers use opposite approaches to examine, control and count quantum particles, said the academy.

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

In an ordinary computer, information is represented in bits, each of which is either a zero or a one. But in a quantum computer, an individual particle can essentially represent a zero and a one at the same time. Making such particles work together, certain kinds of calculations could be done with blazing speed.

One example is the factoring, the process of discovering what numbers can be multiplied together to produce a given number. Quantum computers could radically change people’s lives in the way that classical computers did last century, but a full-scale quantum computer is still decades away, the Nobel judges said.