Goldstone Modes in Bilayer Quantum Hall Systems at ν = 2

20th International Conference on the Application of High Magnetic Fields in Semiconductor Physics

Hama, Y.^1,2 ; Hidaka, Y.^2 ; Tsitsishvili, G.^3 ; Ezawa, Z.F.^4

Department of Physics, University of Tokyo, Tokyo 113-0033, Japan^1

Theoretical Research Division, Nishina Center, RIKEN, Wako 351-0198, Japan^2

Department of Physics, Tbilisi State University, Tbilisi 0128, Georgia^3

Advanced Meson Science Laborary, Nishina Center, RIKEN, Wako 351-0198, Japan^4

关键词: Canted antiferromagnets;    Coherence lengths;    Dispersion relations;    Effective Hamiltonian;    Interlayer phase coherence;    Linear dispersion relations;    Quantum Hall systems;    Systematic method;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/456/1/012012/pdf
DOI  :  10.1088/1742-6596/456/1/012012

来源: IOP

【 摘 要 】

At the filling factor ν=2, the bilayer quantum Hall system has three phases, the spin-ferromagnet phase, the spin singlet phase and the canted antiferromagnet (CAF) phase, depending on the relative strength between the Zeeman energy and interlayer tunneling energy. We present a systematic method to derive the effective Hamiltonian for the Goldstone modes in these three phases. We then investigate the dispersion relations and the coherence lengths of the Goldstone modes. To explore a possible emergence of the interlayer phase coherence, we analyze the dispersion relations in the limit of zero tunneling energy. We find one gapless mode with the linear dispersion relation in the CAF phase.