Author(s):
1. Milan Pantić, Univerzitet u Novom Sadu, Prirodno-matematički fakultet, Departman za fiziku, Serbia

Abstract:
Starting from J1-J2 Heisenberg antiferromagnet on body centered cubic lattice we obtain low-temperature effective field theory in terms of Z2xO(3) nonlinear sigma model. We analyze low energy sector of the nls-m and obtain four branches of type A Nambu-Goldstone bosons. Since excitations display instability at J2/ J1 > 2/3, we identify the critical ratio of exchange integrals to be J2/ J1 = 2/3. On the other hand, GF method predicts critical ratio J2/ J1 = 0.7142. By comparing predictions from Z2xO(3) NLs-M with RPA and QMC, we discuss its applicability on low temperature regime of corresponding Heisenberg model.

Key words:
Heisenberg antiferromagnet,bcc lattice

Thematic field:
SYMPOSIUM A - Science of matter, condensed matter and physics of solid states

Date of abstract submission:
29.07.2019.

Conference:
Contemporary Materials 2019 - Savremeni Materijali

Applied paper from author