Harnessing Quantum Materials to design Antiferromagnetic Topological Textures

计算生态系统使用了全球10%的电力，并产生了2%的排放（与航空业相当）。如果不加以控制，预计到2030年，这一需求将迅速上升至21%。因此，对于能源可持续性，开发具有密集，快速但节能的信息存储和处理的计算平台至关重要。一个新兴的候选人，可以解决这些需求是自旋电子存储器和逻辑，它利用旋转的磁性拓扑结构（TT）作为动态信息位。在过去的十年中，在开发铁磁（FM）TT方面取得了重大进展。然而，它们的实际应用受到杂散磁场、强内部偶极场、低速和侧向运动的影响。为了缓解这些问题，人们对发现反铁磁（AFM）类似物的兴趣激增，预计这些类似物具有鲁棒性，可扩展性，超快和节能性。 我们最近在室温下首次演示了一系列AFM TT。为了实际利用它们，现在至关重要的是开发有针对性的电气控制通路。为此，HQ-AFM将建立一个新的量子材料平台，通过涌现的界面现象提供精致的全电控制的同手性AFM TT。首先，我将设计多铁性异质结构，包含夹在铁电（FE）和重金属（HM）层之间的外延AFM层，托管破坏相互作用以稳定同手性TTs。然后，利用电场开关实现对它们的手征性、尺寸和稳定性的电场调谐。最后，我将利用从HM层注入的基于电流的自旋轨道扭矩来触发它们的成核和超快运动。因此，HQ-AFM将实现AFM TT的非易失性、可逆和可扩展控制，推动AFM拓扑自旋电子学的知识前沿，并为节能的“超越摩尔”计算范式开辟道路。

The computing ecosystem uses 10% of the global electricity and contributes to 2% emissions (at par with aviation). Left unchecked, this demand is expected to rise rapidly to 21% by 2030. Hence, for energy sustainability, it is critical to develop computing platforms with dense, fast yet energy-efficient information storage and processing. An emerging candidate that can address these needs is spintronic memory and logic, which harnesses whirling magnetic topological textures (TTs) as dynamic information bits. In the last decade significant progress was made in developing ferromagnetic (FM) TTs. However, their practical utility has been inhibited by susceptibility to stray magnetic fields, strong internal dipolar fields, slow speeds and sideway motion. To alleviate these issues, there has been a surge of interest in discovering antiferromagnetic (AFM) analogues, which are predicted to be robust, scalable, ultra-fast and energy-efficient. We have recently made the pioneering demonstration of a family of AFM TTs at room temperature. To harness them practically, it is now crucial to develop targeted electrical control pathways. To this effect, HQ-AFM will build a novel quantum materials platform that affords exquisite all-electrical control of homochiral AFM TTs via emergent interfacial phenomena. First, I will design multiferroic heterostructures, containing an epitaxial AFM layer sandwiched between ferroelectric (FE) and heavy-metal (HM) layers, hosting symmetry-breaking interactions to stabilize homochiral TTs. Then, I will exploit FE switching to realize electric-field tuning of their chirality, size and stability. Lastly, I will harness current-based spin-orbit torques injected from the HM layer to trigger their nucleation and ultra-fast motion. HQ-AFM will thus enable non-volatile, reversible and scalable control of AFM TTs, pushing the knowledge frontiers of AFM topological spintronics and forging the path to energy-efficient "beyond-Moore" computing paradigm.