For the last few years,the research interest in magnetoelectric(ME)effect,which is the cross-coupling between ferroelectric and magnetic ordering in multiferroic materials,has experienced a significant revival.The ext...For the last few years,the research interest in magnetoelectric(ME)effect,which is the cross-coupling between ferroelectric and magnetic ordering in multiferroic materials,has experienced a significant revival.The extensive recent studies are not only conducted towards the design of sensors,actuators,transducers,and memory devices by taking advantage of the cross-control of polarization(or magnetization)by magnetic(or electric)fields,but also aim to create a clearer picture in understanding the sources of ME responses and the novel effects associated with them.Here we derive analytical models allowing to understand the striking and novel dynamics of ME effects in multiferroics and further confirm it with atomistic simulations.Specifically,the role of strain is revealed to lead to the existence of electroacoustic magnons,a new quasiparticle that mixes acoustic and optical phonons with magnons,which results in resonances and thus a dramatic enhancement of magnetoelectric responses.Moreover,a unique aspect of the dynamical quadratic ME response under a magnetic field with varying frequencies,which is the second harmonic generation(SHG),has not been discussed prior to the present work.These SHGs put emphasis on the fact that nonlinearities should be considered while dealing with such systems.展开更多
基金S.O.S.,B.X.,and L.B.acknowledge the DARPA Grant Number HR0011-15-2-0038(under the MATRIX program)S.P.acknowledges ONR Grant Number N00014-17-1-2818 and also appreciates support of RFBR 19-52-53030 GFEN+3 种基金C.P.thanks the ARO grant W911NF-16-1-0227B.X.also acknowledges the startup fund from Soochow University and the support from Priority Academic Program Development(PAPD)of Jiangsu Higher Education InstitutionsWe appreciate the support of MRI Grant Number 0722625 from NSF,ONR Grant Number N00014-15-1-2881(DURIP)as well as a Challenge grant from the Department of Defense,and also acknowledge the High Performance Computing Center at the University of Arkansas.
文摘For the last few years,the research interest in magnetoelectric(ME)effect,which is the cross-coupling between ferroelectric and magnetic ordering in multiferroic materials,has experienced a significant revival.The extensive recent studies are not only conducted towards the design of sensors,actuators,transducers,and memory devices by taking advantage of the cross-control of polarization(or magnetization)by magnetic(or electric)fields,but also aim to create a clearer picture in understanding the sources of ME responses and the novel effects associated with them.Here we derive analytical models allowing to understand the striking and novel dynamics of ME effects in multiferroics and further confirm it with atomistic simulations.Specifically,the role of strain is revealed to lead to the existence of electroacoustic magnons,a new quasiparticle that mixes acoustic and optical phonons with magnons,which results in resonances and thus a dramatic enhancement of magnetoelectric responses.Moreover,a unique aspect of the dynamical quadratic ME response under a magnetic field with varying frequencies,which is the second harmonic generation(SHG),has not been discussed prior to the present work.These SHGs put emphasis on the fact that nonlinearities should be considered while dealing with such systems.
