Shot noise of spin current and spin transfer torque
文献类型：期刊论文
| 作者 | Yu, YJ ; Zhan, HX ; Wan, LH ; Wang, B ; Wei, YD ; Sun, QF ; Wang, J |
| 刊名 | NANOTECHNOLOGY
 |
| 出版日期 | 2013 |
| 卷号 | 24期号:15 |
| ISSN号 | 0957-4484 |
| 通讯作者 | Yu, YJ (reprint author), Shenzhen Univ, Coll Phys Sci & Technol, Shenzhen 518060, Peoples R China. |
| 中文摘要 | We report the theoretical investigation of the shot noise of the spin current (S-sigma) and the spin transfer torque (S-tau) for non-collinear spin polarized transport in a spin-valve device which consists of a normal scattering region connected by two ferromagnetic electrodes (MNM system). Our theory was developed using the non-equilibrium Green's function method, and general nonlinear S-sigma - V and S-tau - V relations were derived as a function of the angle theta between the magnetizations of two leads. We have applied our theory to a quantum dot system with a resonant level coupled with two ferromagnetic electrodes. It was found that, for the MNM system, the auto-correlation of the spin current is enough to characterize the fluctuation of the spin current. For a system with three ferromagnetic layers, however, both auto-correlation and cross-correlation of the spin current are needed to characterize the noise of the spin current. For a quantum dot with a resonant level, the derivative of spin torque with respect to bias voltage is proportional to sin theta when the system is far away from resonance. When the system is near resonance, the spin transfer torque becomes a non-sinusoidal function of theta. The derivative of the noise of the spin transfer torque with respect to the bias voltage N-tau behaves differently when the system is near or far away from resonance. Specifically, the differential shot noise of the spin transfer torque N-tau is a concave function of theta near resonance while it becomes a convex function of theta far away from resonance. For certain bias voltages, the period N-tau (theta) becomes pi instead of 2 pi. For small theta, it was found that the differential shot noise of the spin transfer torque is very sensitive to the bias voltage and the other system parameters. |
| 资助信息 | National Natural Science Foundation of China [10947018, 11074171, 11274364]; HKSAR [HKU 705611P] |
| 语种 | 英语 |
| 公开日期 | 2014-01-17 |
| 源URL | [http://ir.iphy.ac.cn/handle/311004/57438]  |
| 专题 | 物理研究所_物理所公开发表论文_物理所公开发表论文_期刊论文 |
| 推荐引用方式 GB/T 7714 | Yu, YJ,Zhan, HX,Wan, LH,et al. Shot noise of spin current and spin transfer torque[J]. NANOTECHNOLOGY,2013,24(15). |
| APA | Yu, YJ.,Zhan, HX.,Wan, LH.,Wang, B.,Wei, YD.,...&Wang, J.(2013).Shot noise of spin current and spin transfer torque.NANOTECHNOLOGY,24(15). |
| MLA | Yu, YJ,et al."Shot noise of spin current and spin transfer torque".NANOTECHNOLOGY 24.15(2013). |
入库方式： OAI收割
来源：物理研究所
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