Department of Physics and Institute for Nanoscience and Engineering, University of Arkansas Fayetteville, Arkansas 72701, USA.
Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049, China.
Phys Rev Lett. 2014 Apr 11;112(14):147601. doi: 10.1103/PhysRevLett.112.147601. Epub 2014 Apr 7.
Using a first-principles-based effective Hamiltonian within molecular dynamics simulations, we discover that applying an electric field that is opposite to the initial direction of the polarization results in a switching of both the polarization and the magnetic chirality vector of multiferroic BiFeO3 at an ultrafast pace (namely, of the order of picoseconds). We discuss the origin of such a double ultrafast switching, which is found to involve original intermediate magnetic states and may hold promise for designing various devices.
利用分子动力学模拟中的基于第一性原理的有效哈密顿量，我们发现，施加一个与极化初始方向相反的电场，会导致多铁性 BiFeO3 的极化和磁手性向量以超快的速度（即皮秒量级）发生反转。我们讨论了这种双超快反转的起源，发现它涉及到原始的中间磁态，这可能为设计各种器件提供了希望。
