7A70.25 - Quantum Levitation and Flux Pinning

Code Number:
7A70.25
Demo Title:
Quantum Levitation and Flux Pinning
Condition:
Good
Principle:
Superconductivity, Flux Pinning
Area of Study:
Modern Physics

Disclaimer

Equipment:
Flux Pinning Superconductors, Liquid Nitrogen, Dewar, and Neodymium Magnets.
Procedure:

See also 5G50.50 in Electricity and Magnetism.

Cool the superconductor and press it into the magnet.  The superconductor should be pinned at that location until it warms up.

You can also place the superconductor onto the magnets and then cool it to Liquid Nitrogen temperature.  The superconductor may rise up off the magnets when it becomes cool, but if it does not you can pick it up and show that it is pinned to the magnet configuration it experienced when it was cooled.

Large Eddy currents in silver may also be observed.  Cool the coins in liquid nitrogen and then gently drop them onto the the magnet array as shown in the video below.  Note that the large silver dollar coins work best for this demonstration.

References:
  • James Lincoln, "Superconductors in the High School Classroom", TPT, Vol. 55, #8, Nov. 2017, p. 506.
  • Ronald Brown, "Demonstrating the Meissner Effect and Persistent Current", TPT, Vol. 38, #3, Mar. 2000, p. 168.
  • P. J. Ouseph, "Levitation of a Magnet Over a Superconductor", TPT, #4, Apr. 1990, p. 205.
  • C. P. Strehlow, M.C. Sullivan, "A Classroom Demonstration of Levitation and Suspension of a Superconductor over a Magnetic Track", AJP, Vol. 77, #9, Sept. 2009, p. 847.
  • A. Badia-Majos, "Understanding Stable Levitation of Superconductors from Intermediate Electromagnets", AJP, Vol. 74, #12, Dec. 2006, p. 1136.
  • E. H. Brandt, "Rigid Levitation and Suspension of High-Temperature Superconductors by Magnets", AJP, Vol. 58, #1, Jan. 1990, p. 43.
  • Warren Pickett and Mikhail Eremets, "The Quest for Room-Temperature Superconductivity in Hydrides", Physics Today, Vol. 72, #5, May 2019, p. 52.
  • Richard J. Fitzgerald, "University Lower Bound on the Dissipation of Superconductors", Physics Today, Vol. 71, #4, Apr. 2017, p. 24.
  • Johanna L. Miller, "Unconventional Superconductivity Discovered in Graphene Bilayers", Physics Today, Vol. 71, #5, May 2018, p. 15.
  • R. Arpaia, S. Caprara, R. Fumagalli, G. De Vecchi, Y. Y. Peng, E. Andersson, D. Betto, G. M. De Luca, N. B. Brookes, F. Lombardi, M. Salluzzo, L. Braicovich, C. Di Castro, M. Grilli, and G. Ghiringhelli, "Dynamical Charge Density Fluctuations Pervading the Phase Diagram of a Cu-Based High-Tc Superconductor", Science, Vol. 365, #6456, Aug. 2019, p. 906.
  • H.-H. Kim, S. M. Souliou, M. E. Barber3, E. Lefrançois, M. Minola, M. Tortora, R. Heid, N. Nandi, R. A. Borzi, G. Garbarino, A. Bosak, J. Porras, T. Loew, M. König, P. J. W. Moll, A. P. Mackenzie, B. Keimer, C. W. Hicks, and M. Le Tacon, "Uniaxial Pressure Control of Competing Orders in a High-Temperature Superconductor", Science, Vol. 362, #6418, Nov. 2018, p. 1040.
  • P. Giraldo-Gallo, J. A. Galvis, Z. Stegen, K. A. Modic, F. F. Balakirev, J. B. Betts, X. Lian, C. Moir, S. C. Riggs, J. Wu, A. T. Bollinger, X. He, I. Božović, B. J. Ramshaw, R. D. McDonald, G. S. Boebinger, and A. Shekhter, "Scale-Invariant Magnetorestistance in a Cuprate Superconductor", Science, Vol. 361, #6401, Aug. 2018, p. 479.
  • P. O. Sprau, A. Kostin, A. Kreisel, A. E. Böhmer, V. Taufour, P. C. Canfield, S. Mukherjee, P. J. Hirschfeld, B. M. Andersen, and J. C. Séamus Davis, "Discovery of Orbital-Selective Cooper Pairing in FeSe", Science, Vol. 357, #6346, July 2017, p. 75.
  • Jearl Walker, "The Amateur Scientist: The Spectra of Streetlights Illuminate Basic Principles of Quantum Mechanics", Scientific American, Vol. 250, #1, Jan. 1984, p. 138.
  • Richard M. Sutton and The American Association of Physics Teachers, "A-11. Glow Discharge Tube", Demonstration Experiments in Physics, 1938, p. 437 - 438.
  • Quantum Experience Packet, Quantum Levitation Starter Kit, Quantum Levitation Maglev Kit, and Quantum Levitation for Undergraduate and High School Teachers.
  • Robert Ehrlich, "L.11. Superconductivity", Turning the World Inside Out and 174 Other Simple Physics Demonstrations, p. 153.

Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist.  The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose.  The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources.  Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks.  These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage.  Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.