近日，德国弗莱堡大学的的Lukas Bruder及其研究团队取得一项新进展。他们使用脉冲整形实现了极紫外域中的强场量子控制。相关研究成果已于2024年12月11日在国际权威学术期刊《自然》上发表。

据悉，在强耦合状态下，定制化的光与物质相互作用能够以高达100%的效率实现对量子系统的操纵，其应用范围从量子信息到光化学不等。虽然使用长波长辐射很容易在价电子层面诱导出强光与物质相互作用，但直到最近，才观察到使用短波长辐射也能产生类似现象，从而能够触及高度激发的多电子和内壳层电子态。然而，由于极端紫外（XUV）和X射线领域缺乏脉冲整形技术，迄今为止还无法实现短波长下强场过程的量子控制。

该研究团队利用种子型自由电子激光器（FEL）FERMI的脉冲整形技术，高保真地实现了氦原子中超快拉比动力学的强场量子控制。该研究的方法揭示了一种强烈的电离连续态修饰效应，这种效应在以往的实验观测中难以捕捉。利用这一效应，研究人员实现了对总电离率的控制，这一成果有望应用于众多极端紫外（XUV）和软X射线实验中。结合近年来在强场少飞秒至阿秒级XUV至软X射线光源方面取得的进展，这项研究结果为实时高效地操纵和选择性控制核心电子过程，以及电子相关现象开辟了一条新途径。

附：英文原文

Title: Strong-field quantum control in the extreme ultraviolet domain using pulse shaping

Author: Richter, Fabian, Saalmann, Ulf, Allaria, Enrico, Wollenhaupt, Matthias, Ardini, Benedetto, Brynes, Alexander, Callegari, Carlo, Cerullo, Giulio, Danailov, Miltcho, Demidovich, Alexander, Dulitz, Katrin, Feifel, Raimund, Fraia, Michele Di, Ganeshamandiram, Sarang Dev, Giannessi, Luca, Glz, Nicolai, Hartweg, Sebastian, von Issendorff, Bernd, Laarmann, Tim, Landmesser, Friedemann, Li, Yilin, Manfredda, Michele, Manzoni, Cristian, Michelbach, Moritz, Morlok, Arne, Mudrich, Marcel, Ngai, Aaron, Nikolov, Ivaylo, Pal, Nitish, Pannek, Fabian, Penco, Giuseppe, Plekan, Oksana, Prince, Kevin C., Sansone, Giuseppe, Simoncig, Alberto, Stienkemeier, Frank, Squibb, Richard James, Susnjar, Peter, Trovo, Mauro, Uhl, Daniel, Wouterlood, Brendan, Zangrando, Marco, Bruder, Lukas

Issue&Volume: 2024-12-11

Abstract: Tailored light–matter interactions in the strong coupling regime enable the manipulation and control of quantum systems with up to unit efficiency, with applications ranging from quantum information to photochemistry. Although strong light–matter interactions are readily induced at the valence electron level using long-wavelength radiation, comparable phenomena have been only recently observed with short wavelengths, accessing highly excited multi-electron and inner-shell electron states. However, the quantum control of strong-field processes at short wavelengths has not been possible, so far, because of the lack of pulse-shaping technologies in the extreme ultraviolet (XUV) and X-ray domain. Here, exploiting pulse shaping of the seeded free-electron laser (FEL) FERMI, we demonstrate the strong-field quantum control of ultrafast Rabi dynamics in helium atoms with high fidelity. Our approach reveals a strong dressing of the ionization continuum, otherwise elusive to experimental observables. The latter is exploited to achieve control of the total ionization rate, with prospective applications in many XUV and soft X-ray experiments. Leveraging recent advances in intense few-femtosecond to attosecond XUV to soft X-ray light sources, our results open an avenue to the efficient manipulation and selective control of core electron processes and electron correlation phenomena in real time.

DOI: 10.1038/s41586-024-08209-y

Source: https://www.nature.com/articles/s41586-024-08209-y