Tunnel current

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A tunnel current is an electrical current that comes about through the quantum mechanical tunnel effect . A current can normally flow through an electrical conductor or semiconductor when an external electrical voltage is applied . Such a current flow does not normally occur through a non-conductor.

However, if the non-conductor in question, which represents the barrier, is very narrow, a current will flow, i.e. the tunnel current. This is described by means of the quantum mechanical wave function , the probability amplitude of which does not instantly become zero when it hits the non-conductor, but decreases exponentially. The square of the magnitude of the wave function at the end of the barrier is proportional to the tunnel current and decreases exponentially with the width of the barrier. A tunnel current only occurs when the electrons find a free place on the other side of the barrier.

Individual evidence

  1. ↑ Marcus Blab: Charge transport measurements on Si (111) surfaces with a multi-tip scanning tunneling microscope . Forschungszentrum Jülich, 2014, ISBN 978-3-89336-997-3 , p. 11 ( limited preview in Google Book search).
  2. ↑ Electronic semiconductor components . Springer-Verlag, 2013, ISBN 978-3-322-84881-9 , pp. 55 ( limited preview in Google Book search).
  3. ↑ Wolfgang Demtröder: Atoms, molecules and solids . Springer-Verlag, 2005, ISBN 978-3-540-27411-7 , pp. 446 ( limited preview in Google Book search).

See also