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Volume 6

Research & Reviews: Journal of Material Sciences

ISSN: 2321-6212

Magnetic Materials 2018

October 22-23, 2018

Page 40

conference

series

.com

October 22-23, 2018 | Rome, Italy

3

rd

International Conference on

Magnetism and Magnetic Materials

Vladyslav O Cheranovskii, Res. Rev. J Mat. Sci. 2018, Volume 6

DOI: 10.4172/2321-6212-C6-028

Peculiarities of the energy spectrum and the magnetic properties of strongly correlated electron

systems on bipartite lattices formed by weakly interacting linear segments

I

t is known that the intermediate plateau in field dependence of magnetization is informative characteristic for molecular ferrimagnets

and some frustrated spin systems. We demonstrate the existence of intermediate magnetization plateau for a family of one-dimensional

bipartite (non-frustrated) spin systems formed by weakly interacting segments and having singlet ground state. In the limit of weak

interactions between segments these systems have a similar structure of the lowest part of the energy spectra and we presented simple

description for above magnetization plateaus by means of perturbation theory. The increase of the interactions between segments leads to

significant modification in the energy spectra and the magnetization curves for our systems. We studied this process numerically by the

density matrix renormalization (DMRG) and QuantumMonte-Carlo (QMC) methods. We also performed numerical studies of the spin-

Peierls instability for our systems and estimated the corresponding critical exponents for the ground state energy. We studied magnetic

properties of the electron systems on finite 2-leg ladder rings formed by weakly interacting rungs and described by infinite-repulsion

Hubbard model. For the numerical and analytical study of the lowest energy states of the above systems, we used cyclic spin permutation

formalism. We found the possibility of jump-wise change of the ground state spin with the increase of the interaction between rungs. To

explain this finite size effect, we derive new modification of magnetic polaron approximation, which agrees well with the results of the

exact diagonalization study.

Figure 1:

Two examples of spin systems studied: linear spin chain and 3-leg ladder fragments having three-site unit cells.

Recent Publications

1. VOCheranovskii, D J Klein, E V Ezerskaya and VV Tokarev (2018) Finite size effects in anisotropic U=∞Hubbard ladder

rings. Journal of Superconductivity and Novel Magnetism 31:1369-1373.

2. V O Cheranovskii, D J Klein, E V Ezerskaya and V V Tokarev (2017) Validity of t-J approximation for extended Hubbard

model with strong repulsion. Low Temperature Physics 43:1622-1625

3. V O Cheranovskii, D J Klein, E V Ezerskaya, V V Tokarev (2017) Lowest energy states of Hubbard ladder model with

infinite electron repulsion. Computational and Theoretical Chemistry 1116:112-116.

4. V O Cheranovskii, E V Ezerskaya, D J Klein and V V Tokarev (2017) Ground state spin of Hubbard model with infinite

electron repulsion. Acta Physica Polonica Series a 131(4):916-918.

Vladyslav O Cheranovskii

V.N. Karazin Kharkiv National University, Ukraine