arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1807.02630physics.opticsphysics.chem-ph
收藏

动力学对称性破缺光谱在高次谐波产生中的高选择性手性鉴别

Highly selective chiral discrimination in high harmonic generation by dynamical symmetry breaking spectroscopy

Ofer Neufeld, Oren Cohen

摘要:

我们提出并数值模拟了一种新的非常稳健和高选择性的飞秒时间分辨手征光谱方法,使用高谐波产生(HHG)。该方法基于手性介质的动力学对称性破缺,并且仅依赖于强烈的电偶极跃迁,而不依赖于电偶极和磁偶极的相互作用。对称性破缺导致以另外的“禁止”谐波形式的强手性信号的发射(即,不从非手性介质发射)。这些手性禁止谐波的强度与介质的对映体过量直接相关,从而产生手性选择性。相反,“允许的”谐波的强度是手性无关的,因此它们可以用作参考,以提供从单个测量的手性选择性,不像以前的时间分辨方案,需要多次测量。我们展示了数值96%的歧视水平,从微观气相排放,远远优于以前的时间分辨方法(选择性应进一步提高时,HHG过程的相位匹配)。我们希望新的方法能产生精确的桌面表征的手性介质在气相中,并为高灵敏度的时间分辨超快探测的动态手性过程。

英文摘要:

We propose and numerically demonstrate a new very robust and highly selective method for femtosecond time-resolved chiral spectroscopy using high harmonic generation (HHG). The method is based on dynamical symmetry breaking from chiral media, and relies only on intense electric-dipole transitions, and not on the interplay of electric and magnetic dipoles. The symmetry breaking results in the emission of a strong chiral signal in the form of otherwise 'forbidden' harmonics (i.e., that are not emitted from achiral media). The intensity of these symmetry-forbidden harmonics is directly correlated to the media's enantiomeric excess, yielding chiral selectivity. On the contrary, the strength of the 'allowed' harmonics is chiral-independent, hence they can be used as a reference to provide chiral selectivity from a single measurement, unlike previous time-resolved schemes that require multiple measurements. We demonstrate numerically 96% discrimination level from microscopic gas phase emission, outperforming by far previous time-resolved methods (the selectivity should be further enhanced when the HHG process is phase matched). We expect the new method to give rise to precise table-top characterization of chiral media in the gas-phase, and for highly sensitive time-resolved ultrafast probing of dynamical chiral processes.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑