TRR 160: Coherent manipulation of interacting spin excitations in tailored semiconductors

自旋激发被认为是一种有吸引力的硬件，因为与凝聚态中的其他激发相比，自旋激发具有优越的相干性质，而且自旋之间的相互作用有可能产生新的集体相。本倡议的主要目标是开发这种巨大的潜力，特别注重使用半导体作为物质基础。展望未来，如果成功，SPINS可能会取代目前为止通过充电实现的一些功能。如果几乎可以任意定制其电学和光学特性的半导体，甚至可以拥有高度可控的磁序和特性，那么信息处理的一体化芯片解决方案就可以被设想出来。这些目标需要阐述先进的材料概念，灵感来自于在获得最高纯度系统和将不同材料组合成杂交材料方面的最新进展。此外，复杂的操作工具将发挥重要作用，更具体地说，是光谱方法的进步。这需要由量子光学技术来指导，以达到最终的灵敏度，同时还需要开发出在多体环境中对自旋进行精细建模的方法。该研究计划细分为三个研究领域：(I)零维自旋系统，(Ii)扩展自旋系统和(Iii)自旋系统的新概念。该项目以TRR的形式组织，结合了IOFE研究所、圣彼得堡国立大学和多特蒙德理工大学的核心专业知识。要研究的系统范围从拥有局域电子和空穴自旋的量子点，到包含超流体旋量极化子凝聚体的具有强烈光-物质耦合的微腔。根据目标磁功能的不同，这些材料体系要么与铁磁或等离子金属结合形成杂化，要么被铁磁氧化物或反铁磁2D系统等新材料取代。这种硬件将帮助我们回答尚未解决的问题，并探索全新的方法。为此，应使用涉及激光和微波辐射的测量和操作工具以及利用超快声学中的声子等新工具来实现对相互作用的自旋的相干控制，其功能在非相干区域无法实现。采用这一办法，红十字委员会可以为信息技术在经典和量子体制中的自旋光电子学的未来发展作出重要贡献。最终目标是将相干自旋效应从基础研究阶段推向技术应用，其表现优于当今最先进的技术。

Spin excitations are considered as attractive hardware because of their superior coherence properties compared to other excitations in condensed matter and the possibility of novel collective phases emerging from interactions among spins. The main goal of the present initiative is to exploit such great potential with a particular focus on using semiconductors as material basis. Prospectively, if successful, spins may take over some of the functionalities so far fulfilled by charges. If semiconductors, whose electrical and optical properties can be tailored almost arbitrarily, could possess even highly-controllable magnetic order and properties, all-in-one-chip solutions for information processing could be envisaged. These goals require elaboration of advanced material concepts inspired by recent progress in obtaining highest purity systems and in combining different materials to hybrids. In addition, a significant role will be played by sophisticated manipulation tools, more specifically by advancements of spectroscopic approaches. This needs to be guided by quantum optical techniques to reach ultimate sensitivity and, at the same time, by the development of elaborate modeling of spins in their many-body environment. The research program is subdivided in three research areas: (i) zero-dimensional spin systems, (ii) extended spin systems and (iii) novel concepts of spin systems. Organized as a TRR, this program combines the core expertise of the Ioffe-Institute, the St. Petersburg State University and the TU Dortmund. The systems to be studied range from quantum dots, hosting localized electron and hole spins, to microcavities with strong light-matter coupling, containing superfluid spinor polariton condensates. Depending on the targeted magnetic functionality, these material systems are either combined with ferromagnetic or plasmonic metals to form hybrids or replaced with novel materials such as ferromagnetic oxides or antiferromagnetic 2D systems. This hardware will help us to answer yet unresolved problems and to explore completely novel approaches. To that end, measurement and manipulation tools involving laser light and microwave radiation as well as novel tools exploiting, e.g., phonons in ultrafast acoustics shall be used to reach coherent control of interacting spins with functionalities that cannot be achieved in the incoherent regime. Following this approach, the ICRC could provide an essential contribution to the future development of spin-optoelectronics for information technologies in the classical and the quantum regime. The ultimate goal is to drive coherent spin effects from the stage of fundamental investigations towards technological applications outperforming the present-day state-of-the-art ones.