Authors
Abstract
Spin tunneling effect in Single Molecule Magnet Fe8 is studied by instanton calculation technique using SU(3) generalized spin coherent state in real parameter as a trial function. For this SMM, tunnel splitting arises due to the presence of a Berry like phase in action, which causes interference between tunneling trajectories (instantons). For this SMM, it is established that the use of quadrupole excitation (g dependence) changes not only the location of the quenching points, but also the number of these points. Also, these quenching points are the steps in hysteresis loops of this SMM. If dipole and quadrupole excitations in classical energy considered, the number of these steps equals to the number that obtained from experimental data.
Keywords
2. A Caneschi, D Gatteschi, R Sessoli, A Barra, L Brunel, M Guillot, Journal of the American Chemical Society, 113, 15 (1991) 5873.
3. J Friedman , M Sarachik , J Tejada, R Ziolo, Phys. Rev. Lett., 76 (1996) 3830-3833.
4. J Hernandez , X Zhang, F Luis, J Bartolom, J Tejada, R Ziolo, Europhys. Lett., 35 (1996) 301-306.
5. L Thomas, F Lionti, R Ballou,D Gatteschi, R Sessoli, B Barabara , Nature 383 (1996) 145-147.
6. B Barbara, R Giraud, W Wernsdorfer, D Mailly, P Lejay, A Tkachuk, H Suzuki, J. Magn. Magn. Mat., 1024 (2004) 272-276.
7. N Ishikawa, M Sugita, W Wernsdorfer, Angew. Chem., 117, (2005) 2991-5.
8. K Wieghardt, K Pohl, I Jibril and G Huttner, Angew. Chem.. Int. Ed. Engl., 23 (1984) 77.
9. C Delfs et al, Inorg. Chem., 32 (1993) 3099.
10. A Barra, P Debrunner, D Gatteschi, Ch Schultz and R Sessoli, Europhys. Lett. 35 (1996) 133.
11. C Sangregorio, T Ohm, C Paulsen, R Sessoli and D Gatteschi, Phys. Rev. Lett., 78 (1997) 4645.
12. R Caciuffo, G Amoretti, A Murani, R Sessoli, A Caneschi and D Gatteschi, Phys. Rev. Lett. 81 (1998) 4744.
13. W Wernsdorfer and R Sessoli, Science, 284 (1999) 133.
14. D Loss, D Divincenzo, and G Grinstein, Phys. Rev. Lett., 69 (1992) 3232.
15. J Von Delft and C Henley, Phys. Rev. Lett., 69 (1992) 3236.
16. A Garg, Europhys. Lett., 22, (1993) 205.
17. E Keçecioğlu and A Garg Phys. Rev. Lett., 88 (2002) 237205.
18. Y Yousefi, Kh Muminov, Iranian Journal of Physics Research, 12, 4 2012 179-183.
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