tunneling probability

Tunneling probability refers to the chance that a particle, like an electron, can pass through a barrier, such as a wall it normally shouldn't be able to cross, based on classical physics. Quantum mechanics treats particles as waves, which can extend beyond barriers. When the wave overlaps the other side, there’s a certain likelihood—called tunneling probability—that the particle appears on the far side, even without enough energy to overcome the barrier. This phenomenon is fundamental in devices like tunnel diodes and is essential in processes like nuclear fusion in stars.