An international team of scientists found that particle tunneling through a potential barrier occurs instantly, and not after a finite time, as recent studies have shown. This is reported by Science Alert.
During the experiment, physicists used hydrogen atoms. The time it takes for electrons to tunnel was measured with an atto clock, a device that generates laser beams lasting a few attoseconds (10 to the minus 18th power of a second) and can calculate when electrons are released from an atom. A thousand ultrashort light pulses with a total power of 30 gigawatts interacted with hydrogen.
Although tunneling was originally thought to be instantaneous, recent studies using multielectron atoms have shown that electrons travel through a potential barrier in a finite nonzero time. However, hydrogen atoms, which have one electron, allowed more accurate measurements and calculations to solve this mystery. The experimental results showed that the observed pattern corresponds to the data obtained in theoretical modeling of instantaneous tunneling.
The tunneling effect, which can be imagined as the passage of an object through a wall, is observed in quantum systems and is impossible in classical mechanics. It consists in the fact that a particle can overcome a potential barrier without having enough energy for this, due to the Heisenberg uncertainty relation. A potential barrier is a region of space that separates two other regions with different or identical potential energies.