arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2011.04343quant-ph
收藏

微扰极限以外的二维光谱学:有限脉冲和探测模式的影响

Two-dimensional spectroscopy beyond the perturbative limit: the influence of finite pulses and detection modes

André Anda, Jared H. Cole

摘要:

超快和多维光谱学为分子系统的动力学提供了一个强大的观察镜。特别是二维电子光谱学(2DES)提供了一个探测相干性和量子系统内的能量流,这是不可能与更传统的技术。虽然外差检测(HD)2DES越来越常见,但最近荧光检测(FD)2DES提供了新的机会,包括单分子实验。然而,在这两种技术中,可能难以明确地识别主导信号的途径。因此,使用2DES的数值模拟是非常重要的,这反过来又需要近似的脉冲方案在一定程度上。在这里,我们采用非微扰时间演化研究有限的脉冲宽度和幅度的2DES信号的影响。在这样做时,我们确定HD和FD检测方案的响应中的关键差异,以及在任一技术中信号被不需要的伪影遮蔽的参数空间区域。以这种方式绘制参数空间提供了选择实验条件的指导,也表明了通常的理论近似在哪些限制下工作良好,哪些限制需要更复杂的方法。

英文摘要:

Ultra-fast and multi-dimensional spectroscopy gives a powerful looking glass into the dynamics of molecular systems. In particular two-dimensional electronic spectroscopy (2DES) provides a probe of coherence and the flow of energy within quantum systems which is not possible with more conventional techniques. While heterodyne-detected (HD) 2DES is increasingly common, more recently fluorescence-detected (FD) 2DES offers new opportunities, including single-molecule experiments. However in both techniques it can be difficult to unambiguously identify the pathways which dominate the signal. Therefore the use of numerically modelling of 2DES is vitally important, which in turn requires approximating the pulsing scheme to some degree. Here we employ non-pertubative time evolution to investigate the effects of finite pulse width and amplitude on 2DES signals. In doing so we identify key differences in the response of HD and FD detection schemes, as well as the regions of parameter space where the signal is obscured by unwanted artefacts in either technique. Mapping out parameter space in this way provides a guide to choosing experimental conditions and also shows in which limits the usual theoretical approximations work well and which limits more sophisticated approaches are required.

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。

↑