Development of an Ultralow Temperature System with In Situ Thin Film Growth Capability

利用主要研究仪器项目的资金，佛罗里达州立大学（FSU）的研究人员将开发一种低温薄膜生长装置，该装置将与一个独特的稀释制冷系统相结合，基础温度为20 mK。使用该装置，pi将能够在超高真空条件下生长一维纳米结构和薄膜，并对其进行原位低温电特性表征。当与纳米级模板掩模结合使用时，可以改变低维样品的横截面积，通过绝缘体-超导体（或“金属”）转变进行调整，并在不进行样品变化或热循环的情况下探测到20 mK的相变。该装置的核心是一个市售的稀释冰箱，它将被定制，以适应必要的附件为薄膜生长。这样的系统将有助于在有限维度下研究量子相变、量子涨落和干涉效应，具有以前无法实现的灵活性和可靠性。从长远来看，原位薄膜生长和低温电测量的独特结合将为许多研究机会打开大门，因为该设备将位于MARTECH，即材料研究与技术中心，由佛罗里达州资助，位于佛罗里达州立大学。该装置将为FSU和周边机构的研究人员，特别是佛罗里达农工大学的研究人员提供方便的超低温通道，以进行更多常规的低温测量，如隧道和磁输运研究

9871085XiongUsing funding from the Major Research Instrumentation program, researchers at Florida State University (FSU) will develop an apparatus for low temperature thin film growth that will be incorporated in a unique dilution refrigeration system with a base temperature of 20 mK. With this apparatus the PIs will be capable of growing one dimensional nanostructures and thin films under ultrahigh vacuum conditions and performing in situ low temperature electrical characterization on them. When used in conjunction with nano-scale stencil masks, the cross-sectional area of a low dimensional sample can be varied, tuning it through the insulator-superconductor (or "metal") transition and probing the phase transition down to 20 mK without undergoing sample change or thermal cycling. The centerpiece of the setup is a commercially available dilution refrigerator, which will be customized to accommodate the necessary accessories for the film growth. Such a system will facilitate studies of quantum phase transition, quantum fluctuations and interference effect under restricted dimensions with previously unattainable flexibility and reliability. %%%The unique combination of in situ thin film growth and low temperature electrical measurement will open the door for many research opportunities in the long run, as the apparatus will be sited at MARTECH, the Center for Materials Research and Technology, which is funded by the state of Florida and located at FSU. The setup will provide researchers at FSU and surrounding institutions, especially Florida A & M University, with convenient access to ultralow temperature for more routine low temperature measurements such as tunneling and magneto-transport studies.***