Of great promise are synthetic antiferromagnet-based racetrack devices in which chiral composite domain walls can be efficiently moved by current. However, overcoming the trade-off between energy efficiency and thermal stability remains a major challenge. Here we show that chiral domain walls in a synthetic antiferromagnet–ferromagnet lateral junction are highly stable against large magnetic fields, while the domain walls can be efficiently moved across the junction by current. Our approach takes advantage of field-induced global energy barriers in the unique energy landscape of the junction that are added to the local energy barrier. We demonstrate that thermal fluctuations are equivalent to the magnetic field effect, thereby, surprisingly, increasing the energy barrier and further stabilizing the domain wall in the junction at higher temperatures, which is in sharp contrast to ferromagnets or synthetic antiferromagnets. We find that the threshold current density can be further decreased by tilting the junction without affecting the high domain wall stability. Furthermore, we demonstrate that chiral domain walls can be robustly confined within a ferromagnet region sandwiched on both sides by synthetic antiferromagnets and yet can be readily injected into the synthetic antiferromagnet regions by current. Our findings break the aforementioned trade-off, thereby allowing for versatile domain-wall-based memory, and logic, and beyond.

基于合成反铁磁体的跑道装置前景广阔，其中手性复合磁畴壁可以通过电流有效移动。然而，克服能源效率和热稳定性之间的权衡仍然是一个重大挑战。在这里，我们表明，合成反铁磁体-铁磁体横向结中的手性畴壁在大磁场下高度稳定，而畴壁可以通过电流有效地穿过结。我们的方法利用了结点独特能量景观中场引起的全局能量势垒，并将其添加到局部能量势垒中。我们证明热波动等效于磁场效应，从而令人惊讶地增加了能垒并在较高温度下进一步稳定结中的畴壁，这与铁磁体或合成反铁磁体形成鲜明对比。我们发现，通过倾斜结可以进一步降低阈值电流密度，而不影响高畴壁稳定性。此外，我们证明手性畴壁可以被牢固地限制在由合成反铁磁体夹在两侧的铁磁体区域内，并且可以很容易地通过电流注入到合成反铁磁体区域中。我们的发现打破了上述权衡，从而允许基于域墙的多功能存储器和逻辑等等。