Quantum Tunneling

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What is Quantum Tunneling?

Quantum tunneling is a distinctively quantum mechanical phenomenon that sounds straight out of a sci-fi narrative. It defies classical physics’ expectations as it involves particles ‘tunneling’ through energy barriers that, theoretically, they should not have the energy to surmount.


For example, imagine an electron approaching an energy barrier. In classical physics, if the electron lacks the requisite energy to overcome the barrier, it would be reflected back.

However, in the quantum realm, there’s a probability that this electron can appear on the other side of the barrier as if it passed right through – hence the term “tunneling.”

This peculiarity arises because particles in quantum mechanics can behave like waves, and these waves do not stop at the barrier but instead slowly decrease in amplitude, allowing for the potential for the particle to exist beyond the barrier.

How Does Quantum Tunneling Work?

Describing the process of quantum tunneling involves delving into the abstract concepts of quantum mechanics.

Unlike classical particles, quantum particles are described by a wave function, which provides probabilities of where the particle may be found.

When such a quantum particle encounters a barrier, its wave function doesn’t abruptly end at the barrier’s edge; it decreases exponentially, extending into and beyond the barrier.

This means there’s a non-zero probability of finding the particle on the other side of the barrier, even if the particle doesn’t technically have enough energy to cross it.

The probability of tunneling happening is influenced by factors such as the width and height of the barrier and the mass of the particle.

Smaller, lighter particles are more likely to tunnel than larger, heavier ones, and a narrower, lower barrier is easier to tunnel through than a wider, higher one.

History of Quantum Tunnelling

Year Event Details
Late 19th – Early 20th centuries Inklings of quantum tunneling First traces of quantum tunneling were linked to the study of radioactivity.
1927 recognition of quantum tunneling Quantum tunneling was officially recognized as a distinct phenomenon by Friedrich Hund, Leonid Mandelstam, and Mikhail Leontovich while studying the implications of the Schrödinger wave equation.
1928 Application to alpha decay Quantum tunneling provided a mathematical explanation for alpha decay. This breakthrough was due to the work of George Gamow, Ronald Gurney, and Edward Condon.
Mid-20th century onward Development of modern technology Quantum tunneling became instrumental in the development of modern technology, including semiconductors, transistors, and diodes.
2016 Discovery of water’s quantum tunneling The quantum tunneling of water was discovered, further contributing to our understanding of this unique phenomenon.

The Bottom Line

Quantum tunneling, while it might sound strange or counterintuitive, is an essential concept in quantum mechanics and has proven to be an integral part of modern technology.

From transistors and diodes to the potential future of wireless communication, this emerging technology holds great promise for propelling technological advancements.

Recent research on graphene-based detectors leveraging quantum tunneling suggests the possibility of exceeding 5G capabilities and redefining wireless communications. This could lead to faster, more efficient data transfer, potentially transforming business operations and boosting overall productivity.

In essence, quantum tunneling is not just a theoretical curiosity of quantum physics or quantum computers.

Its practical implications are extensive and influential, ranging from the microcosm of atomic nuclei to the macrocosm of telecommunication networks.

As our understanding of quantum mechanics continues to grow, so too will the possibilities and applications of the technology.


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Sam Cooling
Crypto & Blockchain Writer
Sam Cooling
Crypto & Blockchain Writer

Sam Cooling is a crypto, financial, and business journalist based in London. Along with Techopedia, his work has been published in Yahoo Finance, Coin Rivet, and other leading publications in the financial space. His interest in cryptocurrency is driven by a passion for leveraging decentralized blockchain technologies to empower marginalized communities worldwide. This includes enhancing financial transparency, providing banking services to the unbanked, and improving agricultural supply chains. Sam has a Master’s Degree in Development Management from the London School of Economics and has worked as a Junior Research Fellow for the UK Defence Academy.