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Journal of Physics Condensed Matter

Spin correlation on the main chain of a quasi-one-dimensional polymer ferromagnet: a density matrix renormalization group study

K.L. Yao, X W Liu, Q M Liu, Gaoyong Sun, Z L Liu

Published Jun 6, 2003• 2 citations
Publisher

Abstract

The spin correlation (SC) function on the main chain of a theoretical model for organic ferromagnets is studied by using a density matrix renormalization group method with both periodic boundary conditions and open boundary conditions (OBCs). It is found that the chain–radical interaction, the on-site electron–electron repulsion, and the electron–phonon coupling affect the SC greatly and play important roles in the stability of the ferromagnetic state. There exist some types of 'weak' OBC, diminishing the alternation of the SC.

DOI
10.1088/0953-8984/15/24/314

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We carry out density matrix renormalization group (DMRG) calculations to study π-topology and spin alignment of an organic π-conjugated spin system in the Hubbard model. We discuss the spin correlation, the energy gap and the lattice configuration in half-filled and doped systems. It is confirmed that electronic doping can alter the spin state, and the spin alignment is influenced by the parity of the total site number N . The electron–electron interaction is in favour of the ferromagnetic stability of the system. For the hall-filled odd case and the hole-doped even case, there exist strong ferromagnetic correlation and large energy gap in π-conjugated spin systems.
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