Physics – Condensed Matter – Strongly Correlated Electrons
Scientific paper
2011-05-05
J. Phys.: Condens. Matter 23 (2011) 146002
Physics
Condensed Matter
Strongly Correlated Electrons
16 pages, 6 figures
Scientific paper
10.1088/0953-8984/23/14/146002
We discuss the magnon spectrum of an antiferromagnet (AF) in a magnetic field $h$ consisting of two interpenetrating AF sublattices coupled by the exchange interaction at T=0. One-ion easy-plane anisotropy is also taken into account. We calculate using the 1/S expansion the gap in the spectrum which is a manifestation of the order-by-disorder effect in this system and the optical magnon mode splitting. Both of these phenomena originate from the inter-sublattice interaction. We calculate also the gap value at $h\approx h_c$ in the leading order of the small parameter $(h_c-h)/h_c$ using the magnon Bose-Einstein condensation treatment, where $h_c$ is the saturation field. By comparing results obtained within these two approaches we conclude that the 1/S expansion gives a qualitatively correct result at $h\sim h_c$ even at large one-ion anisotropy but it overestimates the gap value. The application is discussed of these results to the actively studied AF of the considered type $\rm NiCl_2$-$\rm 4SC(NH_2)_2$ (DTN).
Sizanov Alexey V.
Syromyatnikov Arseny V.
No associations
LandOfFree
Antiferromagnet with two coupled antiferromagnetic sublattices in a magnetic field does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Antiferromagnet with two coupled antiferromagnetic sublattices in a magnetic field, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Antiferromagnet with two coupled antiferromagnetic sublattices in a magnetic field will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-690627