title: Dynamical Piezoelectric and Magnetopiezoelectric Effects in Polar Metals from Berry Phases and Orbital Moments.
abstract: The polarization of a material and its response to applied electric and magnetic fields are key solid-state properties with a long history in insulators, although a satisfactory theory required new concepts such as Berry-phase gauge fields. In metals, quantities such as static polarization and the magnetoelectric θ term cease to be well defined. In polar metals, there can be analogous dynamical current responses, which we study in a common theoretical framework. We find that current responses to dynamical strain in polar metals depend on both the first and second Chern forms, related to polarization and magnetoelectricity in insulators as well as the orbital magnetization on the Fermi surface. We provide realistic estimates that predict that the latter contribution will dominate, and we investigate the feasibility of experimental detection of this effect.
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.|QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands.
authors.forename: Dániel
authors.initials: D
authors.lastname: Varjas
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.
authors.forename: Adolfo G
authors.initials: AG
authors.lastname: Grushin
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.|Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel.
authors.forename: Roni
authors.initials: R
authors.lastname: Ilan
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.|Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Joel E
authors.initials: JE
authors.lastname: Moore