A Spin Chern pump with fully gapped energy and spin spectra
1 National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University Nanjing 210093, China
2 Collaborative Innovation Center of Advanced Microstructures, Nanjing University - Nanjing 210093, China
Received: 16 September 2015
Accepted: 19 October 2015
We propose a topological spin Chern pump using a two-dimensional topological insulator subject to electromagnetic radiations. In each cycle, spin can be continuously pumped into leads, which is attributed to the nonzero spin Chern numbers. In comparison to a previous model (Chen M. N. et al., Phys. Rev. B, 91 (2015) 125117), this system can have a much larger spin pumping conductivity. Moreover, the energy and spin spectra are always gapped in the present system, which makes the spin pumping more stable to perturbations. The spin pumping is an observable effect of the topological invariant spin Chern numbers, which may be useful in spintronic applications.
PACS: 72.25.-b – Spin polarized transport / 73.23.-b – Electronic transport in mesoscopic systems / 75.76.+j – Spin transport effects
© EPLA, 2015