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

这项提议是为了开发一种多功能低温机械手，用于加拿大光源(CLS)的量子材料光谱中心(QMSC)光束线。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，方法是在样品台上引入多用途电接触，使材料能够驱动材料进入量子物质的新相并揭开新相的面纱。这项技术升级旨在实现SPIN+ARPES测量，在调整了前所未有的控制参数范围后，可以探测固体的电子结构，而这些参数在ARPES光谱仪中通常很难或以前不可能实现。该设备将允许用户：(I)驱动电流并对样品施加偏置；(Ii)产生受控磁场以使样品就地磁化；以及(Iii)对样品施加精确且可测量的机械应变。在QMSC，我们使用自旋+ARPES来回答一些最突出的固体物理和量子物质的基本问题，特别关注于奇异现象的出现，如高温超导，由电子关联引起的相干相，以及从拓扑绝缘行为到拓扑超导的拓扑相。微观上的理解，更好的量子材料的设计和工程，以及它们在功能器件中的最终开发，都依赖于我们通过外部刺激以有意和可控的方式诱导和引出这些奇异现象的能力。为此，材料可以通过外部偏压或通过机械应变的结构改变或通过施加磁场来驱动进入新的相。在ARPES实验中实现这些“控制旋钮”的精确调整是一项重大的技术挑战，因为这必须在低温下的超高真空环境中完成。我们建议克服这些困难，并通过重新设计商用6轴冷冻机械手来创建通用解决方案，该机械手带有电子触点-使用此RTI购买-以容纳安装在定制样品支架上的样品。控制电触点上的电压将使其有可能在现场产生磁场，使电流流过样品，并施加精确的机械应变。对于后者，购买了商业RazorBill应变池，可以在样品上提供高度准确和可重复的应变，并对其进行了改造，以容纳在我们的低温样品架上。这一RTI将支持一个长期的实验凝聚态物理研究计划，专注于超导和其他奇异量子现象的研究，但也将为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.