Abstract
When adiabatically varied in time, certain one-dimensional band insulators allow for the quantized noiseless pumping of spin even in the presence of strong spin-orbit scattering. These spin pumps are closely related to the quantum spin Hall system, and their properties are protected by a time-reversal restriction on the pumping cycle. In this paper we study pumps formed of one-dimensional insulators with a time-reversal restriction on the pumping cycle and a bulk energy gap which arises due to interactions. We find that the correlated gapped phase can lead to novel pumping properties. In particular, systems with different ground states can give rise to different classes of spin pumps, including a trivial class which does not pump quantized spin and nontrivial classes allowing for the pumping of quantized spin on average per cycle, where . We discuss an example of a spin pump that transfers an average of spin without transferring charge.
- Received 20 June 2011
DOI:https://doi.org/10.1103/PhysRevB.84.075325
©2011 American Physical Society