University of California, Merced
A Novel Aharonov-Bohm Effect: Macroscopic Quantum Phase Transition Induced by the Vector Potential: Sigma Xi Distinguished Scientist Lecture
Lecture/Seminar | November 19 | 3-5 p.m. | California Room
5200 North Lake Rd, Merced, CA 95343
Raymond Chiao, UC Merced
Sigma Xi presents its second Distinguished Scientist lecture of the Fall semester.
Distinguished Professor and founding faculty member Raymond Chiao offers a lecture entitled "A Novel Aharonov-Bohm Effect: Macroscopic Quantum Phase Transition Induced by the Vector Potential."
An asymmetric hysteresis loop, whose asymmetry is induced by the vector potential arising from the ferromagnetic core of a lead-coated torus, has been observed in a tin ring that is topologically linked with this torus, upon transitions through the critical temperature and critical field of this tin ring.
The spontaneous symmetry breaking within the ferromagnet has thus been observed to be transferred to a broken symmetry associated with the persistent current flowing around the tin ring. This effect occurred even though the electrons within the tin ring could never have experienced any classical forces from the ferromagnet contained within the core of the lead torus because of the magnetic shielding from the Meissner effect of the superconducting lead coating.
Like the Aharonov-Bohm effect, this effect is nonlocal, topological, and quantum mechanical in nature. However, it is macroscopic in its manifestation.
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