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,
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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?
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:
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Neon lamps can also function as amplifiers ;-)
Neon Lamp Tricks! Neon Lamp Multivibrator:
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Citat: "...This is an oscillator circuit using two neon lamps, two resistors, and one capacitor..."
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Solid state negative differential resistance components was discovered several times about 100 years ago:
Cristadyne: Semiconductor archaeology or tribute to unknown precursors:
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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:
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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:
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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:
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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..."
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:
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What is Quantum Tunneling?:
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Shark and Ralphie (not Shrödinger cats this time...) (4:19...):
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National Institute Of Standards And Technology (NIST) (2004, February
2). New Cryogenic Refrigerator Dips Chips Into A Deep Freeze. ScienceDaily:
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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..."
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And now to something completely weird:
Web archive backup: July 22, 1997, The New York Times Company: Signal Travels Farther and Faster Than Light:
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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:
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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..."
University of Illinois at Urbana-Champaign (2013, March 18). Electrons are not enough: Cuprate superconductors defy convention. ScienceDaily:
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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. ..."
How Dr Gunter Nimtz is sending Mozart's 40th Symphony several times faster than the speed of light across 12 cm of laboratory bench in Germany using the tunnel effect:
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:
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The Orbitron. a gallery of atomic orbitals and molecular orbitals on the WWW:
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!
Please explain this - single-photons - not photon clusters:
Markus Pössel: Faster-than-light (FTL) speeds in tunneling experiments: an annotated bibliography:
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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..."
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