What basically is Klein tunneling ?

In summary, Klein tunneling is a phenomenon in which electrons can pass through energy barriers regardless of their width and energy height. It was first described theoretically for 3D massive Dirac electrons by Oskar Klein in 1929. In the α−T3 model, transmission across electrostatic interfaces is found to be perfectly transparent for normal incidence and enhanced for other angles of incidence. This is analogous to the "super", all-angle transmission reported for the dice lattice. The behavior of the particles changes when the barrier potential is approximately equal to rest mass energy. Graphene is the first material in which Klein tunneling was observed experimentally, and it showcases how electrons behave as massless particles and follow relativistic mechanics rather than classical or Sch
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phywithAK
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Recently, in my quantum physics classes i was introduced to the concept of tunneling of particle through a barrier potential and about transmission probability.
Our instructor mentioned about something known as "Klein tunneling".
Can somebody explain to me what is Klein tunneling and why behavior of the particle which is tunneling changes when barrier potential is approximately equal to rest mass energy,
V≅MC2 .
 
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  • #2
phywithAK said:
Recently, in my quantum physics classes i was introduced to the concept of tunneling of particle through a barrier potential and about transmission probability.

one has to look up the following

We investigate Klein tunneling for the α−T3 model, which interpolates between graphene and the dice lattice via parameter α. We study transmission across two types of electrostatic interfaces: sharp potential steps and sharp potential barriers. We find both interfaces to be perfectly transparent for normal incidence for the full range of the parameter α for both interfaces. For other angles of incidence, we find that transmission is enhanced with increasing α. For the dice lattice, we find perfect, all-angle transmission across a potential step for incoming electrons with energy equal to half of the height of the potential step. This is analogous to the “super”, all-angle transmission reported for the dice lattice for Klein tunneling across a potential barrier.

Klein tunneling in the α−T3 model
E. Illes and E. J. Nicol
Phys. Rev. B 95, 235432 – Published 26 June 2017

 
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that 1929 paper may be interesting...

However, the Dirac electrons found in graphene can tunnel through energy barriers regardless of their width and energy height; a phenomenon called Klein tunneling, described theoretically for 3D massive Dirac electrons by the Swedish physicist Oskar Klein in 1929. Graphene was the first material in which Klein tunneling was observed experimentally, as massive Dirac electrons required energy barriers too large to be observed.

Read more at: https://phys.org/news/2011-11-secrets-tunneling-energy-barriers.html#jCp
 
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drvrm said:
that 1929 paper may be interesting...

However, the Dirac electrons found in graphene can tunnel through energy barriers regardless of their width and energy height; a phenomenon called Klein tunneling, described theoretically for 3D massive Dirac electrons by the Swedish physicist Oskar Klein in 1929. Graphene was the first material in which Klein tunneling was observed experimentally, as massive Dirac electrons required energy barriers too large to be observed.

Read more at: https://phys.org/news/2011-11-secrets-tunneling-energy-barriers.html#jCp

Thanks drvrm for this interesting link, so because of the electrons behaving as massless particles they no longer follow the classical physics energy equation
E=P2/2M ,
and tend to follow relativistic mechanics. So that would mean they would not also follow Schrodinger's equation also.
 

Related to What basically is Klein tunneling ?

1. What is Klein tunneling?

Klein tunneling is a quantum mechanical phenomenon where particles can pass through potential barriers without being affected by them. This is in contrast to classical mechanics where particles would be confined by the barrier.

2. How does Klein tunneling occur?

In Klein tunneling, the wave function of a particle is split into two components, one passing through the barrier and one reflecting off of it. These two components then recombine on the other side of the barrier, resulting in the particle appearing to "tunnel" through the barrier.

3. What are the applications of Klein tunneling?

Klein tunneling has potential applications in the field of quantum computing, where it could be used to improve the efficiency of quantum information processing. It also has applications in nanotechnology, where it could be used to create more efficient electron devices.

4. Is Klein tunneling a proven phenomenon?

Yes, Klein tunneling has been experimentally observed in various systems such as graphene and topological insulators. It is a well-established phenomenon in quantum mechanics.

5. Are there any limitations to Klein tunneling?

While Klein tunneling is a fascinating and useful phenomenon, it is not applicable in all scenarios. It is limited to very thin barriers and only occurs when the particle's energy is higher than the barrier's potential energy. Additionally, the phenomenon is only observable at very low temperatures, making it difficult to use in practical applications.

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