Imaging fractionalized excitations and their impact on magnetic interactions in two-dimensional quantum spin liquids

二维量子自旋液体中的分段激发成像及其对磁相互作用的影响

• 批准号: 529232793
• 负责人: Dr. Lucas Schneider
• 金额: --
• 依托单位: Institut für Nanostruktur- und Festkörperphysik (INF)
• 依托单位国家: 德国
• 项目类别: WBP Fellowship
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/529232793?language=en
• 关键词: Imaging; fractionalized; excitations; their; impact

The physics of quantum spin liquids (QSLs) and their fractionalized quasiparticle excitations has fascinated scientists for decades but is difficult to probe experimentally. Interacting spins in conventional magnetic materials order at sufficiently low temperatures, leading to quasi-classical magnetic ground states such as ferromagnetism, antiferromagnetism, and helical order. In contrast, QSLs are exotic states of matter in which competing interactions between spins lead to massive ground state degeneracy. As a consequence, long-range quantum entanglement without long-range magnetic order is found in QSLs, even when approaching absolute zero temperature. Interestingly, the excitations of the QSL state are fractional quasiparticles, such as spinons, visons, or Majorana quasiparticles (MQPs). Renewed interest in QSLs came with the insight that high-temperature superconductivity may emerge from a doped QSL state and that their excitations can have non-Abelian statistics with promising applications for quantum computation. The goal of this proposal is to demonstrate how scanning tunneling microscopy and -spectroscopy combined with electrostatic gating can be used to access the physics of fractionalized quasiparticles and correlated phases in two candidate QSL materials: 1T-Tantalum Diselenide and Alpha Ruthenium Chloride. These materials will be combined with other 2D materials into heterostructures that exhibit novel properties and functionalities. The proposed experiments could potentially lead to the discovery of spinon-mediated magnetic interactions in an electrical insulator, the characterization of a new class of correlation-driven superconductors, as well as real-space imaging of QSL-based topologically protected MQPs.

量子自旋液体（QSL）及其分形准粒子激发的物理学几十年来一直吸引着科学家，但很难通过实验进行探索。传统磁性材料中的相互作用自旋在足够低的温度下有序，导致准经典磁性基态，如铁磁性，反铁磁性和螺旋有序。相比之下，QSL是奇异的物质状态，其中自旋之间的竞争相互作用导致大规模的基态简并。结果表明，即使在接近绝对零度的温度下，在量子超晶格中也存在没有长程磁序的长程量子纠缠。有趣的是，QSL态的激发是分数准粒子，如自旋子、介子或马约拉纳准粒子（MQPs）。对QSL的新兴趣来自于这样的认识，即高温超导性可能来自掺杂的QSL状态，并且它们的激发可以具有非阿贝尔统计，在量子计算中具有有前途的应用。这个建议的目标是演示如何扫描隧道显微镜和光谱结合静电门可以用来访问物理的分馏准粒子和相关的相位在两个候选QSL材料：1 T-二硒化钽和氯化钌。这些材料将与其他2D材料组合成具有新特性和功能的异质结构。拟议的实验可能会导致在电绝缘体中发现自旋介导的磁相互作用，表征一类新的相关驱动超导体，以及基于QSL的拓扑保护MQPs的真实空间成像。