Name: Mohamad Al-Saqer, Graduate Student.
Institue: Iowa State Universiy
Advisor: Bruce N. Harmon, Deputy Director of Ames Labaratory and a distinguished professor in the Physics department at Iowa State University.

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For quantum computing and spin-tronics in general, the influence of a dissipative evnironment on coherence and tunneling in spin systems is crucial. Experimental and theoretical studies of the strongly anisotropic molecular magnets such as Mn12 and Fe8 have provided many insights into the dynamics of quantum spin systems interacting with the dissipative degrees of freedom. However, the class of weakly anisotropic molecular magnets has received much less attention, in spite of the unusual properties they possess [1,2]. In particular, recent experiments have shown that the interaction with phonons during the Landau-Zener transitions in V15 molecules leads to the appearance of "butterfly"-like hysteresis loops [1]. In resent work, we present an extensive theoretical analysis of these experiments. The parameters of the spin-phonon interaction, as well as characteristic properties of the spin and phonon subsystems are determined. We demonstrate that the picture of the phonon bottleneck proposed in Ref. [1] needs considerable modification. The results obtained provide a basis for the study of the interplay between quantum effects and the dissipative environment in weakly anisotropic molecular magnets. In working with such Molecular Magnets, A High Performance techniques are highly needed along with high "Quadrapole" precision in some cases. A parallel computation technique was used and showed a great enhancement in the performance.
[1] I. Chiorescu et al., Phys. Rev. Lett. 84, 3454 (2000).
[2] V. Dobrovitski et al., Phys. Rev. Lett. 84, 3458 (2000).