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Quantum tunneling takes time, new study shows

Experiments tested whether electrons could escape an atom instantaneously

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7:00am, July 26, 2017
electrons illustration

TIME OUT  Electrons can escape their atoms, even if the particles don’t have enough energy to do so, through quantum tunneling. But such tunneling takes time, a new study suggests.

Quantum particles can burrow through barriers that should be impenetrable — but they don’t do it instantaneously, a new experiment suggests.

The process, known as quantum tunneling, takes place extremely quickly, making it difficult to confirm whether it takes any time at all. Now, in a study of electrons escaping from their atoms, scientists have pinpointed how long the particles take to tunnel out: around 100 attoseconds, or 100 billionths of a billionth of a second, researchers report July 14 in Physical Review Letters.

In quantum tunneling, a particle passes through a barrier despite not having enough energy to cross it. It’s as if someone rolled a ball up a hill but didn’t give it a hard enough push to reach the top, and yet somehow the ball tunneled through to the other side.

Although scientists knew that particles could tunnel, until now,

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