为了发展未来的磁数据存储技术,产生局部的超快磁场是根本。迄今为止,将电流脉冲注入到微型线圈和微型带状线中[1~6],以及用高能电子束[7]已实现亚纳秒磁场状态的激发。已提出通过全金属结的自旋极化电流局部注入[8,9]做磁开关元件的有效方法,而且似乎已获得验证[10~13]。在混合型铁磁半导体结构中已观测到自旋注入[14,15]。这里介绍在这种混合结构中几种产生局部超快磁场的方案,其基本元件是用聚焦约150fs激光脉冲光抽运的肖特基二极管。激光脉冲在半导体-金属结产生电流,转而在平面内产生磁场。这种方案结合了局部电流注入技术[11~13,16]和在肖特基势垒上产生快速电流。主要特点包括能在样品平面上沿任何方向快速产生局部场,能通过许多磁元件扫描该磁场,以及能以二极管偏压调谐磁场幅度。 In order to develop the future of magnetic data storage technology, to produce a local ultra-fast magnetic field is fundamental. To date, current pulses have been injected into micro-coils and microstrip lines [1-6] and sub-nanosecond magnetic field excitation has been achieved with high-energy electron beams [7]. It has been proposed that the local injection of spin-polarized current through all-metal junction [8, 9] is an effective method to make the magnetic switching element and seems to have been validated [10-13]. Spin injection has been observed in hybrid ferromagnetic semiconductor structures [14,15]. Here are a couple of ways to create a localized, fast magnetic field in this hybrid structure, the basic element of which is a Schottky diode that is optically pumped at about 150fs laser pulses. The laser pulses create a current in the semiconductor-metal junction, which in turn generates a magnetic field in the plane. This scheme combines local current injection techniques [11-13,16] and produces a fast current on the Schottky barrier. Key features include rapid local field generation in any direction on the sample plane, scanning of the magnetic field by many magnetic elements, and tuning of the magnetic field amplitude with diode bias.