QUANTUM TUNNELLING Meaning and
Definition
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Quantum tunnelling, also known as tunneling, is a phenomenon in quantum mechanics where particles are able to pass through potential barriers that would be classically impossible to surmount. It occurs when a particle, such as an electron, encounters an energy barrier that is higher than its current energy level and lacks the necessary energy to overcome it. In classical physics, the particle would be constrained by the barrier and unable to penetrate it.
However, in quantum mechanics, particles exhibit wave-particle duality, meaning they possess both particle and wave-like properties. This enables them to exhibit a wave-like behavior called wavefunction probability distribution. As a result, there is a nonzero probability that the wave function of a particle extends beyond the barrier, allowing it to "tunnel" through the barrier and appear on the other side.
The probability of tunnelling occurring depends on various factors, including the height and width of the barrier and the energy of the particle. Shorter, narrower barriers are more likely to be tunneled through, and particles with higher energies have a greater chance of tunneling. Conversely, higher and wider barriers reduce the probability of tunneling.
Quantum tunnelling plays a pivotal role in numerous phenomena and applications, such as explaining radioactive decay, electron transport in semiconductor devices, scanning tunneling microscopy, and tunnel diodes. Its discovery and understanding have transformed our understanding of the microscopic world and have paved the way for advancements in quantum technologies.
Etymology of QUANTUM TUNNELLING
The word "quantum tunnelling" has its roots in the field of quantum mechanics and relates to the phenomenon known as "quantum tunneling". Let's break down the etymology of this term:
1. Quantum: This word comes from the Latin word "quantus", meaning "how much" or "how great". In physics, quantum refers to the discrete and indivisible units or packets of energy that certain physical properties, such as light and electrons, can have.
2. Tunnelling: The word "tunnelling" is derived from the English word "tunnel", which can be traced back to the Middle English word "tonel" or "tunel", meaning "tube" or "pipe". A tunnel can be envisioned as a passage through which one can pass, often underground or through an obstacle.
