In situ study of strain- and field-induced phases of quantum matter at the CLS-QMSC Beamline

该建议是一个多用途的低温机械手的发展将用于量子材料光谱学中心（QMSC）光束线在加拿大光源（CLS）。这将极大地丰富我们最先进的自旋和角度分辨光电子能谱（Spin+ARPES）用户设备的能力，通过在样品台上引入多用途电接触，将能够驱动材料进入并揭示量子物质的新相。这一技术升级旨在允许Spin+ARPES测量，在调整前所未有的控制参数范围后探测固体的电子结构，这些参数通常很难或以前不可能在ARPES光谱仪中实现。这一设备将使用户能够：㈠驱动电流并向样品施加偏置; ㈡产生受控磁场，就地磁化样品; ㈢向样品施加精确和可测量的机械应变。 在QMSC，我们使用Spin+ARPES来回答固态物理和量子物质的一些最突出的基本问题，特别关注奇异现象的出现，如高温超导性，电子相关性引起的相干相，以及从拓扑绝缘行为到拓扑超导性的拓扑相。微观理解，更好的量子材料的设计和工程，以及它们在功能设备中的最终利用，都依赖于我们通过外部刺激以故意和受控的方式诱导和引发这些奇异现象的能力。为此，材料可以通过外部电偏压，或通过机械应变进行结构修改，或通过施加磁场被驱动到新的相。在ARPES实验中实现这些“控制旋钮”的精确调谐是一项重大技术挑战，因为这必须在低温超高真空环境中完成。我们建议克服这些困难，并创建一个通用的解决方案，通过重新设计一个商业6轴冷冻机械手与电接触-购买此RTI -主机安装在定制的样品架上的样品。控制电触点上的电压将使原位产生磁场，使电流流过样品，并施加非常精确的机械应变成为可能。对于后者，我们购买了一个商业化的Razorbill应变池，可以在样品上提供高度准确和可重复的应变，并将其安装在我们的低温样品架上。 该RTI将支持实验凝聚态物理学的长期研究计划，重点是超导性和其他奇异量子现象的研究，但也为QMSC@CLS以及我们的国内和国际用户社区提供独特的世界竞争力体验。

This proposal is for the development of a multi-purpose cryo-manipulator to be used at the Quantum Materials Spectroscopy Center (QMSC) beamline at the Canadian Light Source (CLS). This will greatly enrich the capabilities of our state-of-the-art spin- and angle-resolved photoemission spectroscopy (Spin+ARPES) users' facility by introducing multi-purpose electrical contacts onto the sample stage that will enable driving the materials into - and unveiling - novel phases of quantum matter. This technical upgrade is meant to allow Spin+ARPES measurements that probe the electronic structure of solids upon tuning of an unprecedented range of control parameters that are commonly hard or previously impossible to achieve in ARPES spectrometers. This equipment will allow users to: (i) drive currents and apply a bias to the sample; (ii) generate controlled magnetic fields to magnetize the samples in situ; and (iii) apply precise and measurable mechanical strains to the samples. At QMSC we use Spin+ARPES to answer some of the most outstanding fundamental questions of solid state physics and quantum matter, with particular focus on the emergence of exotic phenomena such as high temperature superconductivity, coherent phases induced by electron correlations, and topological phases ranging from topological insulating behavior to topological superconductivity. The microscopic understanding, the design and engineering of better quantum materials, and their ultimate exploitation in functional devices all rely on our ability to induce and elicit these exotic phenomena in a deliberate and controlled manner through external stimuli. To this end, materials can be driven into new phases by external electrical bias, or by structural modification through mechanical strain, or by the application of magnetic fields. Achieving precise tuning of these "control knobs" in an ARPES experiment is a major technical challenge, since this must be done in an ultra-high vacuum environment at cryogenic temperatures. We propose to overcome these difficulties and create a universal solution by reengineering a commercial 6-axis cryo-manipulator with electrical contacts - purchased with this RTI - to host samples mounted on custom-made sample-holders. Controlling the voltages on the electrical contacts will make it possible to generate magnetic fields in-situ, run current through the samples, and to apply an exquisitely precise mechanical strain. For the latter, a commercial Razorbill strain-cell, that can deliver highly accurate and repeatable strain on the samples, is purchased and adapted to be hosted on our cryogenic sample holders. This RTI will support a long-lasting research program in experimental condensed matter physics focused on studies of superconductivity and other exotic quantum phenomena, but also provide QMSC@CLS, as well as our national and international users' community, with a unique world-competitive experience.