- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Tunable Spin Seebeck Diode with Magnonic Spin Tunneling Junction
摘要： We theoretically investigate the spin–wave spin current induced by the spin Seebeck effect in magnonic spin tunneling junctions (MSTJs) for arbitrary magnetization directions. We show that the MSTJ functions as a tunable spin Seebeck diode in which the tunneling spin current can be turned on and off with high efficiency by controlling the magnetization direction.
关键词： spin current,spin Seebeck effect,diode,magnetization direction,magnonic spin tunneling junction
更新于2025-09-23 15:22:29
-
Transport in a thin topological insulator with potential and magnetic barriers
摘要： We study transport across either a potential or a magnetic barrier which is placed on the top surface of a three-dimensional thin topological insulator (TI). For such thin TIs, the top and bottom surfaces interact via a coupling λ which influences the transport properties of junctions constructed out of them. We find that for junctions hosting a potential barrier, the differential conductance oscillates with the barrier strength. The period of these oscillations doubles as the coupling λ changes from small values to a value close to the energy of the incident electrons. In contrast, for junctions with a magnetic barrier, the conductance approaches a nonzero constant as the barrier strength is increased. This feature is in contrast to the case of transport across a single TI surface where the conductance approaches zero as the strength of a magnetic barrier is increased. We also study the spin currents for these two kinds of barriers; in both cases, the spin current is found to have opposite signs on the top and bottom surfaces. Thus this system can be used to split applied charge currents to spin currents with opposite spin orientations which can be collected by applying opposite spin-polarized leads to the two surfaces. We show that several of these features of transport across finite width barriers can be understood analytically by studying the δ-function barrier limit. We discuss experiments which may test our theory.
关键词： magnetic barrier,transport,spin current,potential barrier,topological insulator
更新于2025-09-23 15:21:01
-
Evidence of Pure Spin-Current Generated by Spin Pumping in Interface Localized States in Hybrid Metal-Silicon-Metal Vertical Structures
摘要： Due to the difficulty to grow high quality semiconductors on ferromagnetic metals, the study of spin diffusion transport in Si was only limited to lateral geometry devices. In this work, by using ultra-high vacuum wafer-bonding technique, we have successfully fabricated metal-semiconductor-metal CoFeB/MgO/Si/Pt vertical structures. We hereby demonstrate pure spin-current injection and transport in the perpendicular current flow geometry over a distance larger than 2μm in n-type Si at room temperature. In those experiments, a pure propagating spin-current is generated via ferromagnetic resonance spin-pumping and converted into a measurable voltage by using the inverse spin-Hall effect occurring in the top Pt layer. A systematic study by varying both Si and MgO thicknesses reveals the important role played by the localized states at the MgO/Si interface for the spin-current generation. Proximity effects involving indirect exchange interactions between the ferromagnet and the MgO/Si interface states appears to be a prerequisite to establish the necessary out-of-equilibrium spin-population in Si under the spin-pumping action.
关键词： localized electronic states,wafer-bonding,inverse spin Hall effect,spin-current,spin pumping
更新于2025-09-09 09:28:46
-
[IEEE 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz2018) - Nagoya, Japan (2018.9.9-2018.9.14)] 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Coherent control of femtosecond spin current investigated by polarization dependent terahertz emission spectroscopy in ferromagnetic heterostructures
摘要： Approaches towards highly-efficient generation of controllable ellipitical ferromagnetic nano-heterostructures are demonstrated. The mechanism for the coherent control of femtosecond spin current in ferromagnetic heterostructures are discussed.
关键词： coherent control,ferromagnetic heterostructures,terahertz emission spectroscopy,femtosecond spin current
更新于2025-09-09 09:28:46