Non-invasive imaging and high-fidelity coherent control of surface-supported spins

将单个原子和分子控制在其固有的时空极限内，具有不可或缺的吸引力，几十年来一直推动着基础研究。原子尺度的相互作用和关联也是所有永恒技术进步的基础，从纳米电子学到信息处理。特别是，最近出现了一种新的有吸引力的方法，用于由单个稀土原子和分子制成的纳米级量子比特。这些模型系统中固有的大磁矩、非平凡的原子内和原子间电子关联以及长期的量子相干性，这些都为分子磁学和量子计算研究提供了无数令人兴奋的新可能性。我目前的科学努力致力于理解和控制这种最小的物质构件的量子力学性质，特别是通过以最小侵入性的方式探测它们。然而，解决这类量子系统中的自旋态是一项极具挑战性的任务。到目前为止，只有具有亚原子空间分辨率的扫描隧道显微镜(STM)能够做到这一点，尽管它具有高度的侵入性和工作温度范围(&lt；4K)的限制。原子力显微镜(AFM)使用新型的钻石缺陷中心(NV)，具有无与伦比的磁传感能力、高保真光学读出能力和广泛的工作温度范围，因此有可能克服这些限制。然而，这种方法目前的分辨率不足(几十纳米)，主要是由于所谓的浅NV中心的荧光猝灭。通过将受控表面化学与基于原子力显微镜的操纵技术相结合，我的目标是解决这个问题，以便在原子尺度上实现高度敏感且非侵入性的访问和量子控制。拟议的方案旨在超越STM在这方面的现有能力，同时推广扫描NV磁测量的范围，以解决固态自旋系统的问题。通过这项计划，我将瞄准由镧系元素单自旋吸附或作为人造2D晶格嵌入的原子级量子体系结构，以接近室温稳定的量子比特阵列。

Controlling individual atoms and molecules at their native spatio-temporal limit has an indispensable appeal that has driven fundamental research for decades. Atomic-scale interactions and correlations are also the basis of all timeless technological progress, ranging from nanoelectronics to information processing. In particular, a new attractive avenue has recently emerged for nanoscale quantum bits made of individual lanthanide atoms and molecules. The intrinsic large magnetic moment, non-trivial intra- as well as inter-atomic electron correlations, and long-term quantum coherence in these model systems altogether offer a myriad of new exciting possibilities across molecular magnetism and quantum computing research. My present scientific effort is devoted to understand and control quantum mechanical properties of such smallest building blocks of matter, especially by probing them in the least invasive manner. However, addressing the spin states in such quantum systems is an extremely challenging task. So far, only scanning tunneling microscopy (STM) with subatomic spatial resolution is capable of achieving this, albeit being highly invasive and limited with the scope of operational temperature (<4 K). Atomic force microscopy (AFM) using novel defect centers in diamond (NV) has the potential to overcome these limitations, given their unparalleled magnetic sensing capability, high-fidelity optical readout, and broad operational range of temperature. However, this method currently suffers from insufficient resolving power (tens of nm) primarily due to fluorescence quenching in so-called shallow NV centers. By combining controlled surface-chemistry with AFM-based manipulation techniques, I aim to resolve this in order to achieve highly sensitive and yet non-invasive access and quantum control at the atomic scale. The proposed programme is designed to surpass the current capabilities of STM in this context, while simultaneously generalizing the scopes of scanning NV-magnetometry for addressing solid-state spin systems. Through this programme I will target atomic-scale quantum architectures made of lanthanide single spins either adsorbed or embedded as artificial 2D lattice, for approaching room-temperature stable qubit arrays.