The main 1/2 magnetization plateau in Shastry-Sutherland magnets: Effect of the long-range Ruderman-Kittel-Kasuya-Yosida interaction

¹ Institute for Advanced Materials and Laboratory of Quantum Engineering and Quantum Materials, South China Normal University - Guangzhou 510006, China
² Department of Physics and TcSUH, University of Houston - Houston, TX, 77204, USA
³ Laboratory of Solid State Microstructures, Nanjing University - Nanjing 210093, China

^(a) qinmh@scnu.edu.cn
^(b) liujm@nju.edu.cn
^(c) zren@uh.edu

Received: 12 November 2013
Accepted: 6 January 2014

Abstract

The ordering of the classical Ising model on the Archimedean lattice that is topologically equivalent to the Shastry-Sutherland one is studied in order to understand the fascinating magnetic properties experimentally observed in rare-earth tetraborides such as TmB₄. The long-range Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction which is expected to be predominant in these systems is taken into account, and the magnetization plateaus and rich ordering behaviors depending on the Fermi wave vector are investigated in details by Monte Carlo simulation. The experimental 1/2 magnetization step can be qualitatively reproduced and its stability against the change of is confirmed, suggesting that the coupling between conduction electrons and localized moments may play an important role in modulating the magnetization behaviors in these systems.