Climate Change Physics; Precision Laser Spectroscopy; and Ultracold Atom Microtrap Arrays

气候变化物理学；

• 批准号: RGPIN-2017-03717
• 负责人: vanWijngaarden, William
• 金额: $ 1.53万
• 依托单位: York University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=763122
• 关键词: Climate; Change; Physics; Precision; Laser

Our research in the broad area of General Physics focuses on 3 distinct areas.1) Climate Change Physics: The 2014 Intergovernmental Panel on climate Change report warns the last 3 decades have been the warmest since 1850 due to the highest levels of greenhouse gases in the past 800,000 years. Our work first checks archival climate records for inhomogeneities due to abrupt changes in instruments or procedure. Next, the statistical significance of trends is examined. The Earth's surface temperature has increased by about 1^o C in the last century. However, decadal temperature fluctuations such as the recently termed global warming hiatus since 2000 are poorly understood. Our objective is to examine discrepancies between observations and theory to better understand the anthropogenic contribution to climate change. We also plan to examine the perturbation of spectral lineshapes from a characteristic Voigt profile due to line mixing of closely spaced CO2 infrared transition caused by atmospheric collisions. This is critical to estimate radiative forcing used by global climate models.2) Precision Laser Spectroscopy: This encompasses the precise laser spectroscopic measurement of fine and hyperfine structure of neutral and single ionized Li. Recent advances in theory enable very precise computation of wavefunctions of few electrons atoms. This enabled us to determine the 6,7Li relative nuclear charge radius to a few parts times 10^-18 meters. We are doing an optical double resonance experiment to measure the hyperfine splitting of the 6Li+ 1s2p 3P state. Each ion is first laser excited and then proceeds through a cavity resonant with the microwave transition. The longer term objective is to measure the fine structure interval separating the 6Li+ 1s2p 3P (J=0,1,2) levels to determine the fine structure constant with an uncertainty of approximately one part per billion.3) Atom Microtrap Arrays: Ultracold atoms are ideal for precision measurements as their Doppler shifts are negligible. We created Canada's first Bose Einstein Condensate at temperatures below 100 nanoKelvins. We invented a microtrap consisting of 2 concentric loops having radii 60 and 132 microns carrying oppositely oriented currents. This generates a 3 dimensional trap whose position relative to the chip surface can be adjusted by applying a bias magnetic field perpendicular to the chip surface which is important for developing surface sensors. The microtraps can be daisy chained together to create a one or two dimensional microtrap array. We plan to demonstrate our proposed atom conveyor that transports atoms among a two dimensional microtrap lattice and also study interactions between atoms at neighbouring lattice sites. Eventually we would like to generate a 2 dimensional array of microtraps, each containing a single ultracold atom, where the atoms are entangled with each other to study quantum information.

我们在普通物理学的广泛领域的研究集中在3个不同的领域。1）气候变化物理学：2014年政府间气候变化专门委员会的报告警告说，由于过去80万年来温室气体的最高水平，过去30年是自1850年以来最温暖的。 我们的工作首先检查档案气候记录的不均匀性，由于仪器或程序的突然变化。接下来，研究趋势的统计意义。 在上个世纪，地球表面的温度上升了约1摄氏度。 然而，年代际温度波动，如最近被称为全球变暖中断自2000年以来知之甚少。 我们的目标是检查观测和理论之间的差异，以更好地了解人类活动对气候变化的贡献。 我们还计划研究的扰动光谱线型的特征Voigt配置文件由于线混合的近距离CO2红外跃迁大气碰撞所造成的。 这对估计全球气候模型使用的辐射强迫至关重要。2）精密激光光谱学：这包括对中性和单电离锂的精细和超精细结构的精密激光光谱测量。 最近理论上的进展使得能够非常精确地计算少数电子原子的波函数。 这使我们能够确定6，7 Li的相对核电荷半径为10^-18米的几分之一。 我们正在进行光学双共振实验，测量6Li+1 s2 p 3 P态的超精细分裂。 每个离子首先被激光激发，然后通过与微波跃迁共振的腔体前进。 长期目标是测量分离6Li+1 s2 p 3 P（J= 0，1，2）能级的精细结构间隔，以确定精细结构常数，其不确定性约为十亿分之一。3）原子微阱阵列：超冷原子是精确测量的理想选择，因为它们的多普勒频移可以忽略不计。 我们创造了加拿大第一个温度低于100纳开尔文的玻色爱因斯坦凝聚体。 我们发明了一种微陷阱，由2个同心环组成，半径为60和132微米，携带相反方向的电流。 这产生了三维陷阱，其相对于芯片表面的位置可以通过施加垂直于芯片表面的偏置磁场来调节，这对于开发表面传感器是重要的。 微阱可以菊花链连接在一起以产生一维或二维微阱阵列。 我们计划展示我们提出的原子输送器，该输送器在二维微陷阱晶格中输送原子，并研究相邻晶格位置原子之间的相互作用。 最终，我们希望生成一个二维微陷阱阵列，每个微陷阱包含一个超冷原子，原子相互纠缠以研究量子信息。