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Quantum Interference of Tunneling Paths in a Molecular Nanomagnet Jonathan R. Friedman, Amherst College, DMR 1006519. Single-molecule nanomagnets are the smallest bistable magnets. Their magnetic moment can “tunnel” from up to down directions.
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Quantum Interference of Tunneling Paths in a Molecular NanomagnetJonathan R. Friedman, Amherst College, DMR 1006519 • Single-molecule nanomagnets are the smallest bistable magnets. • Their magnetic moment can “tunnel” from up to down directions. • The Mn12-tBuAc molecule has four-fold rotational symmetry, reflected in its energy landscape. • A magnetic field HT applied along the energetically unfavorable “hard axis” induces quantum interference between tunneling paths. • At certain values of HT, this interference “turns off” tunneling. • An abrupt increase in the rate at which spins flip directions is observed when tunneling turns back on at slightly higher values of HT.
Quantum Interference of Tunneling Paths in a Molecular NanomagnetJonathan R. Friedman, Amherst College, DMR 1006519 Research by Undergraduate Students • The research on this project was done almost exclusively by undergraduate students, under the supervision of the PI. • Spencer Adams (Amherst College ’13) worked on this project after his sophomore and junior years. He prepared the rotator used in the experiment, mounted the sample, took data, and performed analysis and numerical simulations. • He is lead author on a paper about to be submitted for publication. Other student coauthors are Eduardo H. da Silva Neto ‘08, and John Ware ‘11. • Spencer is now starting his senior honors thesis in the PI’s lab.