制备量子态可控的超冷极性分子离子的研究

项目名称： 制备量子态可控的超冷极性分子离子的研究

项目编号： No.11474317

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 童昕

作者单位： 中国科学院武汉物理与数学研究所

项目金额： 110万元

中文摘要： 制备并研究超冷（T~1mK）分子离子已经成为目前在超冷物理与超冷化学领域最前沿、最具有挑战性的科学研究方向之一。申请人曾在国际上首次利用协同冷却和阈值光电离相结合的方法，在离子阱中成功制备了单一量子态的非极性超冷氮(N2+)分子离子，其量子态纯度接近100%，量子态寿命达到15分钟以上（Phys. Rev. Lett. 105,143001 (2010)）。本项目将应用此技术于具有永久偶极矩（极性）的分子离子（如HD+）上,研究在协同冷却过程中电荷与电偶极矩之间相互作用对振转量子态的影响,并利用低温恒温器延长振转量子态寿命,最终实现对极性分子离子内部和外部自由度的全面精确控制。所制备的超冷极性分子离子将具有在空间上静止（囚禁时间~小时，动能~mK）和较长量子态寿命（~分钟）的特点，这将为测量超高精度分子离子光谱和研究超冷环境下碰撞反应中的量子效应奠定实验基础。

中文关键词： 超冷分子离子；激光冷却；协同冷却；离子阱；精密测量

英文摘要： The emerging field of ultracold (defined as temperature T ~ 1 mK) molecular matter is probably one of the most vibrant fields in contemporary physics and chemistry. The applicant has developed a novel method to produce ultracold and quantum-state selected APOLAR molecular ions(N2+). The near-uniform selectivity in the preparation of the ground rovibrational levels has been achieved in ion traps using sympathetic cooling and resonance-enhanced threshold photoionization. The measured state lifetimes reach the order of 15 minutes. (Editors' Suggestion and Viewpoint paper in Phys. Rev. Lett. 105, 143001 (2010)). Building on the extensive expertise of the applicant in the fields of molecular photoionization and the generation of cold molecular ions, the present proposal is centered on the development of an experimental method to produce quantum-sate selected POLAR molecular ions (e.g.HD+). The study will focus on the effect of electric charge-dipole interaction on the quantum states of molecular ions during the sympathetic cooling process. In addition, a cryostat will be employed to extend the state lifetimes of initially prepared quantum states in molecular ions. Finally, POLAR molecular ions with almost stationary (trapping time > hours, T~mK) position in the laboratory space and very long state lifetimes (> minutes) can be obtained. The ultracold molecular ions will be introduced into a wide range of novel and adventurous applications, for example, 1)using sympathetically cooled molecular ions to perform ultra-high precision spectroscopy; 2)using sympathetically cooled molecular ions to study quantum phenomena in ultra-low collisional energy dynamics.

英文关键词： Ultracold molecular ions;Laser cooling;Sympathetic cooling;Ion trap;Precision measurement