Development of the half-metal spin switch and its application tothe logic circuit

采用Co_2MnSi基半金属Heusler合金电极和MgO势垒的磁隧道结（MTJs）在低温和室温下的隧道磁电阻（TMR）比分别为1275%和350%。该TMR比在Heusler合金电极的MTJs中最高。大的TMR效应对于自旋开关器件的应用是理想的。另外，通过两个MTJs串联的器件中的电压，成功地控制了TMR比。结果表明，该器件可以作为逻辑电路使用。

Magnetic tunnel junctions (MTJs) with Co_2MnSi based half-metallic Heusler alloy electrodes and an MgO barrier showed very large tunnel magneto resistance (TMR) ratio of 1275% at low temperature and 350% at room temperature. This TMR ratio is the highest among the MTJs with Heusler alloy electrodes. The large TMR effect is desirable for application to the spin-switch device. In addition, the TMR ratio was successfully controlled by the voltage in the device that two MTJs were connected in series. This result indicates that the fabricated device can be used as the logic circuit.