Closed-loop cryocooler for continuing an ongoing research on helium nanodroplets

点击翻译按钮获取中文摘要

NEED and URGENCY. One of my ongoing research initiatives, started in 2017, is on quantum control of molecular dynamics inside superfluid helium by means of a unique tool of an optical centrifuge. The project requires a cryogenic cooler, which I have been borrowing from a colleague (Dr. Takamasa Momose at UBC/Chemistry). Dr. Momose will need his cooler back at the beginning of 2020 (his letter is attached to this application). Without the cryocooler available to me, the project will stall, forcing one PhD and one MSc student to change their research topic at a critical time, when first preliminary results have been finally emerging in the latest experiments.******RESEARCH PROGRAM. In 2014, my UBC research group has built a unique laser instrument an “optical centrifuge”, and used it to create and study new and exotic molecular objects, known as “molecular super-rotors”. Super-rotors are ultrafast rotating molecules whose coherent rotation is controlled by the laser field. Our centrifuge is one of three in the world and the only one in Canada. It is also the only centrifuge worldwide in which the three fundamental parameters of molecular “super-rotation” its frequency, directionality and phase can be controlled and measured directly. The centrifuge enabled us to carry out a number of molecular studies, impossible in any other research laboratory. Until now, we have investigated the properties of molecular super-rotors in the regime, where quantum correlations and many-body physics are of little importance. Recently, I started expanding this research to studying rotational dynamics of molecules embedded in many-body quantum systems using controlled laser spinning of molecules inside helium nanodroplets. More than 70 years ago, superfluidity was probed on a macroscopic scale by a mechanically controlled rotating top. Similar studies at the nanoscale proved impossible due to the lack of controllable microscopic rotors. An optical centrifuge makes these studies a reality, and my group is ideally positioned to take the lead.******ADVANCEMENT of KNOWLEDGE and TRAINING. Controlled activation of molecular rotation inside quantum superfluids will provide us with an opportunity to study the dynamics of a rotating object interacting with complex quantum systems. Better understanding of such dynamics will have direct impact on the development of future quantum technologies, which are expected to revolutionize secure communications, computer analysis of biological systems, and sensing of small changes in electrical, magnetic and gravitational fields. Helium nanodroplets have long been recognized as ideal nanocryostats due to their ability to cool single molecules inside their transparent and non-reactive environment. Aside from quantum studies, they are used in spectroscopy, chemical physics and biology research. Opportunities to learn and use this cryogenic technology will provide my students with a very important skill, which is hard to acquire anywhere else.*****