Giant electrothermal conductivity and spin-phonon coupling in an antiferromagnetic oxide.
The application of weak electric fields ( less, similar 100 V/cm) is found to dramatically enhance the lattice thermal conductivity of the antiferromagnetic insulator CaMnO3 over a broad range of temperature about the Néel ordering point (125 K). The effect is coincident with field-induced detrapping of bound electrons, suggesting that phonon scattering associated with short- and long-ranged antiferromagnetic order is suppressed in the presence of the mobilized charge. This interplay between bound charge and spin-phonon coupling might allow for the reversible control of spin fluctuations using weak external fields.
Chiorescu
C
C
Department of Physics, University of Miami, Coral Gables, Florida 33124, USA.
Neumeier
J J
JJ
Cohn
J L
JL