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Tunneling

Discussion in 'Electronic Design' started by George Herold, Mar 25, 2013.

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  1. Hi Guys, I’m back from the APS March meeting.
    I had a request from a Physics Prof for Quantum Mechanics experiments.

    “What sort of QM?”, I asked. (There being QM in almost everything
    these days.)
    “Tunneling”, was the reply.
    I mentioned there was tunneling in low voltage Zeners and in tunnel
    diodes.

    Now I’ve never looked at low voltage zeners, but in theory tunneling
    should give a current that increases exponentially with the voltage.
    Figure 4 here,
    http://www.diodes.com/datasheets/ds30410.pdf
    seems to show such behavior for the two lowest voltages.

    I’m not sure how to ‘show’ that it’s tunneling though.
    (A forward biased diode shows the same exponential I/V.)
    I suppose I could look at the shot noise and perhaps show that it’s
    not an avalanche process.

    So I have two questions;
    Anyone know of a good review paper on low voltage zener physics.
    And are there any tunnel diodes still in production?

    Thanks,
    George H.
     
  2. Glenn

    Glenn Guest

    On 25/03/13 18.40, George Herold wrote:
    ....
    Hi George

    You can make/discover your own tunneldiodes - actually components with
    negative differential resistance:


    By Nyle Steiner K7NS 2001.
    Zinc Negative Resistance RF Amplifier for Crystal Sets and Regenerative
    Receivers Uses No Tubes or Transistors:
    http://www.sparkbangbuzz.com/els/znrfamp2-el.htm

    -

    Neon lamps can also function as amplifiers ;-)

    Neon Lamp Tricks! Neon Lamp Multivibrator:
    http://donklipstein.com/sillyne2.html
    Citat: "...This is an oscillator circuit using two neon lamps, two
    resistors, and one capacitor..."

    -

    Solid state negative differential resistance components was discovered
    several times about 100 years ago:

    Cristadyne: Semiconductor archaeology or tribute to unknown precursors:
    http://www.a-reny.com/iexplorer/cristadyne.html
    Quote: "...In 1923, Oleg Losev [O. V. Lossev, Lossew] (1903-1942) ( See
    link below ) managed to make a high frequency generator using such a
    detector. But it was polarized. This indicates that this diode had a
    characteristic curve in which a negative slope was present. And this
    makes one think of the tunnel effect diode invented a half a century
    later...These layouts where part of what one called CRYSTADYNE [or
    Cristadyne, Crystodyne ] systems. But in those days, the technical
    performance and industrial ease of the new increasing valve technology
    made these layouts to be ignored, and then forgotten..."


    The Wireless World and Radio Review. October 1, 1924 and October 8,
    1924: "The Crystal As A Generator And Amplifier" by Victor Gabel.


    Radio News, September, 1924, pages 294-295, 431: The Crystodyne Principle:
    http://earlyradiohistory.us/1924cry.htm
    Quote: "...SEVERAL experimenters have observed that some contacts, such
    as crystal and metal or crystal and carbon generally employed as
    detectors may produce undamped oscillations of any frequency, exactly as
    the vacuum tube oscillator. The same contact may also be utilized as an
    amplifier. Oscillating crystals are not new since they were investigated
    as far back as 1906 by well known engineers, but it was not until lately
    that a Russian engineer, Mr. O. V. Lossev, succeeded in finding some
    interesting uses for oscillating crystals..."


    Radio News, September, 1924, page 291: A Sensational Radio Invention By
    HUGO GERNSBACK:
    http://earlyradiohistory.us/1924sens.htm
    Quote: "...Stated in a few words, the invention encompasses an
    oscillating crystal...In other words, THE CRYSTAL NOW ACTUALLY
    REPLACES THE VACUUM TUBE. That this is a revolutionary radio
    invention need be emphasized no further. [Here Hugo Gernsback was way
    ahead of his time]...We can not only detect with the crystal, but we can
    also amplify with it...we can now also transmit with the Crystodyne,
    and, as a matter of fact, a number of students in Russia have actually
    sent messages with such sets over distances of more than three-quarters
    of a mile during the past few months..."


    Bell Labs – The Transistor – Other Claims to the Invention:
    http://www.beatriceco.com/bti/porticus/bell/belllabs_transistor1.html
    Quote: "...This effect, he stated, was discovered by Dr W. H. Eccles in
    1910, and remarked: “It is hard to realize that it took about ten years
    for practical active crystal-diode circuits to appear, in spite of
    Ditcham's reminder—circuits that included both RF and AF
    amplification...Most of the credit for creating practical devices [of
    this kind] goes to O. V. Lossev of Russia, whether or not he knew of
    Eccles' pioneer work a decade earlier..."


    Glenn

    PS: Happy nutting...or neon lamping...
     
  3. Glenn

    Glenn Guest

    On 25/03/13 18.40, George Herold wrote:
    ....
    Hi George

    A little about negative [differential] resistance:

    http://en.wikipedia.org/wiki/Negative_resistance

    Glenn
     
  4. Glenn

    Glenn Guest

  5. Hi Glenn, Thanks, I'm not so much looking for a negative resistance
    device as I am for tunneling.

    (If I had a tunnel diode on hand I'd want to look at the I-V curve at
    very low voltage.. way before the first peak in current.)

    Hmm maybe frustrated total internal reflection would be easier?

    George H.
     
  6. $2 each for the NOS Russian GaAs ones isn't bad.

    Aeroflex offers Ge ones, but I bet they're a lot more $$.
     
  7. Do you think these are still being made in Russia?

    George H.
     
  8. Glenn

    Glenn Guest

    On 25/03/13 19.58, George Herold wrote:
    ....
    Hi Goerge

    Here are some tunneling devices:

    DIY:
    Quantum Tunneling on Your Kitchen Table:
    http://web.archive.org/web/20050306140327/www.altair.org/Qtunnel.htm
    Quote: "...
    In this Homegrown Quantum Tunnel experiment, the Quantum Barrier is big
    enough to see (more than a inch wide), and made of household materials.
    ....
    In this experiment we will use giant photons travelling in paraffin to
    tunnel under a barrier of air.
    ...."


    Video: Quantum tunneling on the kitchen table:


    What is Quantum Tunneling?:


    Shark and Ralphie (not Shrödinger cats this time...) (4:19...):



    National Institute Of Standards And Technology (NIST) (2004, February
    2). New Cryogenic Refrigerator Dips Chips Into A Deep Freeze. ScienceDaily:
    http://www.sciencedaily.com/releases/2004/02/040202071058.htm
    Quote: "... The refrigerator is made from a sandwich of nomal-
    metal/insulator/superconductor junctions. When a voltage is applied
    across the "sandwich," high-energy (hot) electrons tunnel from the
    normal metal through the insulator and into the superconductor. As the
    hottest electrons leave, the temperature of the normal metal drops
    dramatically..."


    -

    And now to something completely weird:

    Web archive backup: July 22, 1997, The New York Times Company: Signal
    Travels Farther and Faster Than Light:
    http://web.archive.org/web/20081227...a.edu/~dzierba/HonorsF97/Week1/NYTJuly22.html
    Quote: "..."We find," Chiao said, "that a barrier placed in the path of
    a tunneling particle does not slow it down. In fact, we detect particles
    on the other side of the barrier that have made the trip in less time
    than it would take the particle to traverse an equal distance without a
    barrier -- in other words, the tunneling speed apparently greatly
    exceeds the speed of light. Moreover, if you increase the thickness of
    the barrier the tunneling speed increases, as high as you please..."


    Markus Pössel: Faster-than-light (FTL) speeds in tunneling experiments:
    an annotated bibliography:
    http://www.aei.mpg.de/~mpoessel/Physik/FTL/tunnelingftl.html
    Quote: "...An experiment of theirs, where a single photon tunnelled
    through a barrier and its tunneling speed (not a signal speed!) was 1.7
    times light speed, is described in Steinberg, A.M., Kwiat, P.G. & R.Y.
    Chiao 1993: "Measurement of the Single-Photon Tunneling Time" in
    Physical Review Letter 71, S. 708--711..."

    Glenn
     
  9. Glenn

    Glenn Guest

    Is this related?:


    University of Illinois at Urbana-Champaign (2013, March 18). Electrons
    are not enough: Cuprate superconductors defy convention. ScienceDaily:
    http://www.sciencedaily.com/releases/2013/03/130319091727.htm
    Citat: "...
    "This result is telling us that the physics cannot be described by
    electrons alone," Phillips said. "This means that the cuprates are even
    weirder than previously thought: Something other than electrons carries
    the current."
    ....
    Now the researchers are exploring possible candidates for
    current-carriers, particularly a novel kind of excitation called
    unparticles.
    ...."

    Glenn
     
  10. Do I think so? Nope, but that and $1.60 will get you a Tim Horton's
    coffee.
     
  11. Yeah the frustrated TIR of which I spoke.

    Hmm that's OK except the last bit, The electron spending some time in
    the nucleous is *not* due to tunneling.
    (Oh well no ones perfect.)
    Oh, at low temperatures Josephson junctions show tunneling with a
    vengenace!

    George H.
     
  12. Glenn

    Glenn Guest

  13. Glenn

    Glenn Guest

    On 25/03/13 21.25, George Herold wrote:
    ....
    ....

    Hi George

    Is it because of the standing space-time electron waves ;-)

    Milo Wolff's Quantum Science Corner's: The Quantum Universe:

    Quote: "...Actually, in the H atom both the electron wave-structure and
    the proton have the same center. The electron's structure can be
    imagined like an onion – spherical layers of waves around a center. The
    amplitude of the waves decreases like the blue standing wave in the
    bottom diagram. There are no point masses – no orbits, just waves...".

    Atomic Orbitals:
    http://www.chemistry.nmsu.edu/studntres/chem111/resources/notes/atomic_orbitals.html

    The Orbitron. a gallery of atomic orbitals and molecular orbitals on the
    WWW:
    http://winter.group.shef.ac.uk/orbitron/

    Glenn
     
  14. Jeroen

    Jeroen Guest

    Bah.

    All these experiments have in common that they send the shortest
    possible pulse of whatever signal through a saturating medium.
    As a result, what gets through is a strongly attenuated fraction
    of just the leading edge. Due to the bandwidth limits, both input
    and output are still roughly the same Gaussian shape.

    They then usually scale up the output pulse to disguise the
    attenuation and cry: Look! Faster than light transmission!

    Jeroen Belleman
     
  15. Glenn

    Glenn Guest

    Hi Jeroen

    Please explain this - single-photons - not photon clusters:


    Markus Pössel: Faster-than-light (FTL) speeds in tunneling experiments:
    an annotated bibliography:
    http://www.aei.mpg.de/~mpoessel/Physik/FTL/tunnelingftl.html
    Quote: "...An experiment of theirs, where a single photon tunnelled
    through a barrier and its tunneling speed (not a signal speed!) was 1.7
    times light speed, is described in Steinberg, A.M., Kwiat, P.G. & R.Y.
    Chiao 1993: "Measurement of the Single-Photon Tunneling Time" in
    Physical Review Letter 71, S. 708--711..."

    Glenn
     
  16. Glenn

    Glenn Guest

    Sorry the link leaped forward in time:
    http://web.archive.org/web/20111229192231/http://quantummatter.com/articles/see_an_electron.html

    Glenn
     
  17. A bit more data on them:-

    http://goo.gl/Mwjkh
     
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