Download Numerical Study on ESR of Nanomagnet V and Dzyaloshinsky-Moriya In- teraction

Numerical Study on ESR of Nanomagnet V15 and Dzyaloshinsky-Moriya Interaction
Manabu Machidaa , Toshiaki Iitakab , and Seiji Miyashitac
a
Institute of Industrial Science, The University of Tokyo, Komaba, Tokyo 153-8505, Japan
Ebisuzaki Computational Astrophysics Laboratory, RIKEN (The Institute of Physical and Chemical
Research), Wako, Saitama 351-0198, Japan
c
Department of Physics, Graduate School of Science, The University of Tokyo, Hongo, Tokyo 113-0033,
Japan
b
We develop an efficient numerical method to obtain the ESR absorption of nanoscale molecular magnets.
Our new method realizes O(N ) calculation both in computer memory and computation time. The method
avoids direct diagonalization with the help of the random vector technique and the Chebyshev polynomial
expansion, and obtain the ESR of interacting quantum many-body systems at finite temperature.
Recently, lots of interesting experimental results have been reported on molecular magnets. On the other
hand, theoretical study on such magnets is difficult since the size N of the Hamiltonian is finite but is
usually too large to diagonalize directly (for example, N = 215 = 32768 for nanomagnet V15 ).
We calculate the temperature dependence of the intensity of the ESR absorption curve of nanomagnet
V15 .1 The calculated data are consistent with the previously obtained experimental data.
1
M. Machida, T. Iitaka, and S. Miyashita, to appear in J. Phys. Soc. Jpn. Suppl. (2005).
Sorting category: Cb Magnetism and properties of solids
Keywords: nanomagnets, ESR, kubo formula
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