以色列魏茨曼科学研究所Edvardas Narevicius研究团队揭示了通过探测冷碰撞中的弹性和反应散射来确定量子共振的性质的方法。 这一研究成果于2020年11月30日发表在国际顶尖学术期刊《自然—化学》。

散射共振在物理和化学碰撞过程中起着核心作用。由于散射波函数的空间定位，它们有助于建立对碰撞动力学的直观理解。对于位于离心势垒后的短距离反应区内的共振，反应速率的尖峰是特征信号，最近在低能碰撞的最新实验中观察到。

然而，如果共振发生在反应区域之外，则弹性散射大部分会被修正。这可能是由于上述势垒共振（经典轨道的量子模拟）引起的。通过在合并束实验中探测亚稳态氦与氘分子的弹性散射和非弹性散射，研究人员区分了量子共振的性质——隧道共振与势垒共振——并通过计算相应的散射波函数进行了验证。

附：英文原文

Title: Determining the nature of quantum resonances by probing elastic and reactive scattering in cold collisions

Author: Prerna Paliwal, Nabanita Deb, Daniel M. Reich, Ad van der Avoird, Christiane P. Koch, Edvardas Narevicius

Issue&Volume: 2020-11-30

Abstract: Scattering resonances play a central role in collision processes in physics and chemistry. They help build an intuitive understanding of the collision dynamics due to the spatial localization of the scattering wavefunctions. For resonances that are localized in the reaction region, located at short separation behind the centrifugal barrier, sharp peaks in the reaction rates are the characteristic signature, observed recently with state-of-the-art experiments in low-energy collisions. If, however, the localization occurs outside of the reaction region, mostly the elastic scattering is modified. This may occur due to above-barrier resonances, the quantum analogue of classical orbiting. By probing both elastic and inelastic scattering of metastable helium with deuterium molecules in merged-beam experiments, we differentiate between the nature of quantum resonances—tunnelling resonances versus above-barrier resonances—and corroborate our findings by calculating the corresponding scattering wavefunctions.

DOI: 10.1038/s41557-020-00578-x

Source: https://www.nature.com/articles/s41557-020-00578-x