Quantum tunneling

Introduction to Quantum Tunneling

Quantum tunneling is one of the most mind-boggling concepts in quantum mechanics. It refers to the ability of a particle to tunnel through a potential barrier, even if the particle’s energy is less than the potential energy of the barrier. In classical physics, a particle would never be able to cross a barrier if it does not possess enough energy to overcome the barrier. However, in quantum mechanics, particles can exhibit wave-like properties, enabling them to tunnel through barriers that seem impenetrable.

How Does Quantum Tunneling Work?

The mechanism of quantum tunneling involves the wave-like properties of particles. Particles, such as electrons, can behave as both particles and waves at the same time. When an electron approaches a potential barrier, it can either get reflected off the barrier, pass through it or get trapped inside the barrier. If the energy of the electron is less than the barrier’s energy, there is a probability that the electron can tunnel through the barrier. The probability of tunneling depends on the thickness and height of the barrier, as well as the electron’s energy.

Applications of Quantum Tunneling

Quantum tunneling has several applications in various fields of science and technology. One of the most significant applications is in the field of electronics. The phenomenon of tunneling is exploited in the construction of tunnel diodes, which are used in high-speed switching circuits. Quantum tunneling is also used in scanning tunneling microscopy (STM), a technique that allows scientists to study the properties of surfaces on an atomic scale. In addition, tunneling is essential in the functioning of transistors, which are the fundamental components of modern electronic devices.

Example of Quantum Tunneling in Action

An example of quantum tunneling is nuclear fusion, which powers the sun and other stars. The process of fusion involves the collision of two positively charged nuclei, which repel each other due to their like charges. In classical physics, the nuclei would never collide due to the barrier of the repulsive force. However, in quantum mechanics, there is a probability that the nuclei can tunnel through the barrier and collide, resulting in nuclear fusion. Without quantum tunneling, the sun and stars would not be able to exist.