Quantum Tunneling Is Not Instantaneous, Physicists Show - Scientific American

Quantum Tunneling Is Not Instantaneous, Physicists Show - Scientific American

Quantum tunnelling takes time

Quantum tunnelling — when an atom shimmies its way through a barrier in a way forbidden by classical physics — is not instantaneous. The finding addresses a long-standing mystery about the effect, which underlies everything from photosynthesis to nuclear fusion. Physicists cooled a gas of rubidium atoms and ushered them towards a 1.3-micrometre-thick barrier made of laser light. While the atoms were inside the barrier, their spins atoms slowly rotated under the influence of a magnetic field. The researchers calculated from the spins that, for the atoms with the lowest energy that could get them through the barrier, the crossing took 0.61 milliseconds.

Scientific American | 7 min readReference: Nature paper