Theory of Electron Spin Resonance in One-dimensional Topological Insulators with Spin-orbit Couplings

抄録

Edge states, namely low-energy degrees of freedom localized at the ends, arise in one-dimensional systems with a non-trivial topological nature, such as Haldane chain and one-dimensional topological insulators. Electron Spin Resonance (ESR) is an ideal probe to detect and analyze edge states, and it was indeed successfully applied to edge states of Haldane chains. Here we consider ESR in one-dimensional electron systems with a spin-orbit interaction. The anisotropic nature of the spin-orbit interaction in the spin space leads to a nontrivial ESR line shape. The ESR spectrum for a finite chain is calculated precisely based on Kubo formula, and then contributions from bulk states and edge states are identified separately, by changing the boundary condition. Dependence of each contribution on the temperature, the chemical potential, the magnitude and the direction of the magnetic field is studied systematically.