Waintal Xavier, Brouwer Piet W
CEA, Service de Physique de l'Etat Condensé, Centre d'Etude de Saclay, F-91191 Gif-sur-Yvette cedex, France.
Phys Rev Lett. 2003 Dec 12;91(24):247201. doi: 10.1103/PhysRevLett.91.247201. Epub 2003 Dec 10.
We investigate theoretically the magnetization dynamics of a conducting magnetic nanoparticle weakly coupled to source and drain electrodes, under the assumption that all relaxation comes from exchange of electrons with the electrodes. In the regime of sequential tunneling, the magnetization dynamics is characterized by a relaxation time t(1), which strongly depends on temperature, bias voltage, and gate voltage. While a direct measure of a nanoparticle magnetization might be difficult, we find that t(1) can be determined through a time resolved transport measurement. For a suitable choice of gate voltage and bias voltage, the magnetization performs a bias-driven Brownian motion regardless of the presence of anisotropy.
我们在所有弛豫均源于与电极的电子交换这一假设下，从理论上研究了与源电极和漏电极弱耦合的导电磁性纳米粒子的磁化动力学。在顺序隧穿 regime 中，磁化动力学由弛豫时间 t(1) 表征，该弛豫时间强烈依赖于温度、偏置电压和栅极电压。虽然直接测量纳米粒子的磁化可能很困难，但我们发现 t(1) 可以通过时间分辨输运测量来确定。对于合适的栅极电压和偏置电压选择，无论是否存在各向异性，磁化都进行偏置驱动的布朗运动。
