Fun with Quantum Levitation

Pre­pare to have your mind blown.

You may have seen lev­i­ta­tion tricks per­formed by magi­cians, but rest assured that they can’t beat this: quan­tum lev­i­ta­tion. The video above was cap­tured at the 2011 ASTC con­fer­ence, a gath­er­ing of sci­en­tists in Bal­ti­more, Mary­land, with the pur­pose of demon­strat­ing “how sci­ence cen­ters and muse­ums are putting new ideas to prac­ti­cal use to serve their com­mu­ni­ties.” The School of Physics and Astron­o­my at Tel-Aviv Uni­ver­si­ty has put togeth­er this physics exper­i­ment show­cas­ing quan­tum super­con­duc­tors locked in a mag­net­ic field.

While the video fails to explain the sci­ence of what is hap­pen­ing here, the com­ple­men­tary web­site is help­ful. The white round disk (essen­tial­ly a sap­phire wafer coat­ed with a thin lay­er of yttri­um bar­i­um cop­per oxide) is cooled to below neg­a­tive 185 degrees C. At that tem­per­a­ture (dubbed the crit­i­cal tem­per­a­ture), the mate­r­i­al becomes super­con­duc­tive, mean­ing that it has zero elec­tri­cal resis­tance. From the web­site:

Super­con­duc­tiv­i­ty and mag­net­ic field do not like each oth­er. When pos­si­ble, the super­con­duc­tor will expel all the mag­net­ic field from inside. This is the Meiss­ner effect. In our case, since the super­con­duc­tor is extreme­ly thin, the mag­net­ic field DOES pen­e­trate. How­ev­er, it does that in dis­crete quan­ti­ties (this is quan­tum physics after all! ) called flux tubes.

Inside each mag­net­ic flux tube super­con­duc­tiv­i­ty is local­ly destroyed. The super­con­duc­tor will try to keep the mag­net­ic tubes pinned in weak areas (e.g. grain bound­aries). Any spa­tial move­ment of the super­con­duc­tor will cause the flux tubes to move. In order to pre­vent that, the super­con­duc­tor remains “trapped” in midair.

And in case you’re won­der­ing: are there prac­ti­cal appli­ca­tions for quan­tum lev­i­ta­tion? The answer, of course, is yes!

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Eugene Buchko is a blog­ger and pho­tog­ra­ph­er liv­ing in Atlanta, GA. He main­tains a pho­to­blog, Eru­dite Expres­sions, and writes about what he reads on his read­ing blog.

H/T Engad­get