title: Aharonov-Casher effect in exchange interactions in a Wigner crystal.
abstract: We theoretically study the effects of spin-orbit coupling on spin exchange in a low-density Wigner crystal. In addition to the familiar antiferromagnetic Heisenberg exchange, we find general anisotropic interactions in spin space if the exchange paths allowed by the crystal structure form loops in real space. In particular, it is shown that the two-electron exchange interaction can acquire ferromagnetic character.
authors.affiliation: Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA.
authors.forename: Yaroslav
authors.initials: Y
authors.lastname: Tserkovnyak
authors.forename: Markus
authors.initials: M
authors.lastname: Kindermann