Nonlocal Piezoresponse of LaAlO3/SrTiO3 Heterostructures

Electro-Mechanical Response of Top-Gated LaAlO3/SrTiO3 Heterostructures

LaAlO3/SrTiO3 heterostructures are known to exhibit a sharp, hysteretic metal-insulator transition (MIT) with large enhanced capacitance near depletion. To understand the physical origin of this behavior, the electromechanical response of top-gated LaAlO3/SrTiO3 heterostructures is probed using two simultaneous measurement techniques: piezoforce microscopy (PFM) and capacitance spectroscopy. PFM measurements reveal local variations in the hysteretic response, which is directly correlated with capacitance measurements. The enhanced capacitance at the MIT is linked to charging/discharging dynami…

Dependence of nonlocal Gilbert damping on the ferromagnetic layer type in FM/Cu/Pt heterostructures

We have measured the size effect in nonlocal Gilbert relaxation rate in FM(t$_{FM}$) / Cu (5nm) [/ Pt (2nm)] / Al(2nm) heterostructures, FM = \{ Ni$_{81}$Fe$_{19}$, Co$_{60}$Fe$_{20}$B$_{20}$, pure Co\}. Common behavior is observed for three FM layers, where the additional relaxation obeys both a strict inverse power law dependence $ΔG =K \:t^{n}$, $n=-\textrm{1.04}\pm\textrm{0.06}$ and a similar magnitude $K=\textrm{224}\pm\textrm{40 Mhz}\cdot\textrm{nm}$. As the tested FM layers span an order of magnitude in spin diffusion length $λ_{SDL}$, the results are in support of spin diffusion, rathe…

Electrical spin injection from ferromagnet into an InAs heterostructures through MgO tunnel barrier

We have investigated electrical spin injection from Ni81Fe19 into an InAs quantum well through MgO tunneling barrier for potential application to InAs-based spin field effect transistor. Injected spin polarized current were detected in both nonlocal and local spin valve set-ups and the spin diffusion length and spin injection efficiency were analyzed. The spin diffusion length was estimated to be 1.6 μm in nonlocal set-up at 1.4 K. The spin polarization of Ni81Fe19/MgO/InAs as-deposited sample was relealed to be 6.9 %, while increased spin polarization of 8.9 % was observed by additional therm…

横向多层金属异质结构中非局域轨道电流的超快太赫兹探测

Ultrafast THz probing of nonlocal orbital current in transverse multilayer metallic heterostructures

该研究利用飞秒光激发产生的太赫兹发射，探测金属多层异质结构中的非局域轨道电流及轨道—电荷电流转换，并通过温度依赖测量区分轨道与自旋贡献。

Engineered spatial inversion symmetry breaking in an oxide heterostructure built from isosymmetric room-temperature magnetically ordered components

The oxide heterostructure [(YFeO$_3$)$_5$(LaFeO$_3$)$_5$]$_{40}$, which is magnetically ordered and piezoelectric at room temperature, has been constructed from two weak ferromagnetic AFeO$_3$ perovskites with different A cations using RHEED-monitored pulsed laser deposition. The polarisation arises through the removal of inversion centres present within the individual AFeO$_3$ components. This symmetry reduction is a result of combining ordering on the A site, imposed by the periodicity of the grown structure, with appropriate orientations of the octahedral tilting characteristic of the perov…

一维界面诱导的实空间贝里曲率梯度编码于横向异质结构中的自旋-谷耦合非线性光电流

1D Interface-Induced Real-Space Berry Curvature Gradient Encoded in SpinValley-Coupled Nonlinear Photocurrent in Lateral Heterostructure

本研究在单层横向异质结构中观察到由一维界面诱导的贝里曲率偶极子驱动的自旋-谷耦合圆光生伏特效应，为谷电子学提供了新平台。