Ledesma-Martin José Omar, Galindez-Ruales Edgar, Krishnia Sachin, Fuhrmann Felix, Tran Minh Duc, Gupta Rahul, Gasser Marcel, Go Dongwook, Kamra Akashdeep, Jakob Gerhard, Mokrousov Yuriy, Kläui Mathias
Institute of Physics, Johannes Gutenberg University Mainz, 55099 Mainz, Germany.
Max Planck Graduate Center Mainz, 55122 Mainz, Germany.
Nano Lett. 2025 Feb 26;25(8):3247-3252. doi: 10.1021/acs.nanolett.4c06056. Epub 2025 Feb 14.
In magnetic systems, angular momentum is carried by spin and orbital degrees of freedom. Nonlocal devices, comprising heavy-metal nanowires on magnetic insulators like yttrium iron garnet (YIG), enable angular momentum transport via magnons. These magnons are polarized by spin accumulation at the interface through the spin Hall effect (SHE) and detected via the inverse SHE (iSHE). The processes are generally reciprocal, as demonstrated by comparable efficiencies when reversing injector and detector roles. However, introducing Ru, which enables the orbital Hall effect (OHE), disrupts this reciprocity. In our system, magnons polarized through combined SHE and OHE and detected via iSHE are 35% more efficient than the reverse process. We attribute this nonreciprocity to nonzero spin vorticity, resulting from varying electron drift velocities across the Pt/Ru interface. This study highlights the potential of orbital transport mechanisms in influencing angular momentum transport and efficiency in nonlocal spintronic devices.
在磁性系统中，角动量由自旋和轨道自由度携带。由诸如钇铁石榴石（YIG）等磁性绝缘体上的重金属纳米线组成的非局域器件，能够通过磁振子实现角动量传输。这些磁振子通过自旋霍尔效应（SHE）在界面处由自旋积累极化，并通过逆自旋霍尔效应（iSHE）进行检测。这些过程通常是可逆的，当反转注入器和探测器的角色时，效率相当就证明了这一点。然而，引入能够实现轨道霍尔效应（OHE）的钌会破坏这种可逆性。在我们的系统中，通过自旋霍尔效应和轨道霍尔效应共同极化并通过逆自旋霍尔效应检测的磁振子比反向过程效率高35%。我们将这种不可逆性归因于非零自旋涡度，这是由铂/钌界面上不同的电子漂移速度导致的。这项研究突出了轨道输运机制在影响非局域自旋电子器件中的角动量传输和效率方面的潜力。
