1 Quantum Tunneling

This is a fundamental quantum effect, or phenomenon, that was first reported as a theoretical possibility and quantum calculation in “Nature” by Brian Josephson (subsequently awarded a Nobel Laureate in Physics for this important theoretical prediction/calculation) from The Cavendish Laboratory of the University of Cambridge, UK. (The paper also served as the contents of Brian Josephson’s doctoral (MA) thesis at the University of Cambridge, UK). Subsequently, the first experimental proof for quantum tunneling was obtained at Bell Labs., in the USA, inspired by P. W. Anderson (Nobel Laureate in Physics shared in 1978 with Sir Neville Mott of The Cavendish Laboratory, and Van Vleck); many subsequent experiments verified its existence, and also numerous devices, such as the transistor, were invented that utilized it. P.W. Anderson, was also the first theoretical physicist to verify the quantum calculations made by Brian Josephson and support the publication of the latter’s results. The Nobel prize for the transistor went however to Dr. John Bardeen, (a former Professor of Physics at the University of Illinois at Urbana in the Loomis Laboratory), who had initially rejected as ‘impossible’ Josephson’s manuscript submitted to “Nature” describing the quantum tunneling effect.

Quantum tunneling consists in the ability of quantum particles, such as electrons, protons, nuclei, etc. to tunnel through finite potential barriers with definite (non-zero) probabilities. (Classically, this could be seen as ‘ghosts’ passing through solid walls!). At first, it was rejected by certain eminent peer-reviewers as being ‘impossible’, much the same as the flying of objects with density greater than air was rejected at first by certain French academicians that specialized in fluid mechanics who did not wish to acknowledge the existence in nature of flying birds.

Note: One may also regard the quantum tunneling (Josephson effect) as a consequence of the Heisenberg uncertainty principle as applied, for example, to thin junctions, as in transistors and superconducting layer junctions separated by thin insulating layers.

Thus, Josephson junctions were also designed and are currently utilized with superconducting materials/layers. In nature, most–if not all– enzymes function as biocatalysts based on quantum tunneling effects to reduce the free energy requirements for a bewildering number of biocatalytic reactions.