Topological Charge Pumping in Excitonic Insulators
Abstract
We show that in excitonic insulators with s wave electronhole pairing, an applied electric field (either pulsed or static) can induce a p wave component to the order parameter, and further drive it to rotate in the s +i p plane, realizing a Thouless charge pump. In one dimension, each cycle of rotation pumps exactly two electrons across the sample. Higher dimensional systems can be viewed as a stack of onedimensional chains in momentum space in which each chain crossing the Fermi surface contributes a channel of charge pumping. Physics beyond the adiabatic limit, including in particular dissipative effects is discussed.
 Publication:

Physical Review Letters
 Pub Date:
 January 2021
 DOI:
 10.1103/PhysRevLett.126.027601
 arXiv:
 arXiv:2008.00134
 Bibcode:
 2021PhRvL.126b7601S
 Keywords:

 Condensed Matter  Strongly Correlated Electrons;
 Condensed Matter  Mesoscale and Nanoscale Physics
 EPrint:
 5 pages, 4 figures