What Devices and Barriers are Used in Quantum Tunneling Experiments?

[forex10]

On pages 23 & 24 of the book Superforce by Paul Davies - The unusual
occurances of electrons or other particles as they approach a barrier
are described.

I would like to know what devices are used in these experiments? What
device shoots out electrons or other particles in a single stream at a
fairly low rate? Also what kind of barriers are used?

It is too bad that Davies did not elaborate further on this or give out
more info. I would guess an electron beam produced by a CRT is too
energetic or intense for these experiments. Hopefully some one can help
out here.

Joel

 

[ZapperZ]

On pages 23 & 24 of the book Superforce by Paul Davies - The unusual
occurances of electrons or other particles as they approach a barrier
are described.

I would like to know what devices are used in these experiments? What
device shoots out electrons or other particles in a single stream at a
fairly low rate? Also what kind of barriers are used?

It is too bad that Davies did not elaborate further on this or give out
more info. I would guess an electron beam produced by a CRT is too
energetic or intense for these experiments. Hopefully some one can help
out here.

Joel

In a scanning tunneling microscope, the material being probe has a very sharp tip hovering just barely above the surface. A potential bias across the tip-sample causes electrons to tunnel across the vacuum gap between these two.

In planar tunnel junction, you make layers of a material separated by a thin, insulating region. Again, charge carriers can tunnel across the barrier than a sufficient potential is applied across the barrier.

etc etc...

Zz.