近日，德国雷根斯堡大学U. Höfer团队报道了石墨烯中朗道-齐纳-马约拉纳跃迁的亚周期成像。这一研究成果发表在2026年10月28日出版的《自然》杂志上。

强光场为全光调控相干电子轨迹、能带工程以及塑造物质的涌现相开辟了全新可能。要揭示其背后的量子机制，需要直接可视化能带结构中光波驱动的电子运动。尽管光电子动量显微术已在多个光周期平均的意义上对光激发电子进行了成像，但亚周期能带结构成像仍局限于较小的电子动量。然而，量子材料中光波驱动的基本过程往往遍及整个动量空间。

研究组引入覆盖整个第一布里渊区的阿秒精度亚周期能带结构成像，并可视化最强基本却难以捉摸的强场过程之一：非绝热朗道-齐纳-马约拉纳隧穿。在石墨烯类狄拉克能带结构中，强场驱动加速与周期性朗道-齐纳-马约拉纳带间隧穿的相互作用，表现为布里渊区边缘载流子分布的相干亚周期位移与畸变。极端非热电子分布还使研究组能够区分相互竞争的散射过程，并评估其对相干电子调控的影响。研究组对场驱动电子运动的全景视图，使对量子材料强场调控的微观理解达到了新的高度。

附：英文原文

Title: Subcycle videography of Landau–Zener–Majorana transitions in graphene

Author: Eggers, V., Inzani, G., Meierhofer, M., Mnster, L., Helml, J., Wallauer, R., Zajusch, S., Ito, S., Machtl, L., Yin, H., Kumpf, C., Bocquet, F. C., Bao, C., Gdde, J., Tautz, F. S., Huber, R., Hfer, U.

Issue&Volume: 2026-10-28

Abstract: Strong light fields have unlocked entirely new possibilities to tailor coherent electron trajectories, engineer band structures and shape emergent phases of matter all-optically1,2,3,4,5,6,7,8,9. Unravelling the underlying quantum mechanisms requires a visualization of the lightwave-driven electron motion10,11 directly in the band structure. Although photoelectron momentum microscopy has imaged photoexcited electrons averaged over many cycles of light12,13,14,15,16,17,18,19, subcycle band-structure videography has been limited to small electron momenta8,20. Yet, lightwave-driven elementary processes in quantum materials often occur throughout momentum space. Here we introduce attosecond-precision, subcycle band-structure videography covering the entire first Brillouin zone and visualize one of the most fundamental but elusive strong-field processes: non-adiabatic Landau–Zener–Majorana tunnelling. The interplay of strong-field-driven acceleration within the Dirac-like band structure of graphene and periodic Landau–Zener–Majorana interband tunnelling manifests in a coherent subcycle displacement and distortion of the carrier distribution at the Brillouin zone edge. The extremely non-thermal electron distributions also allow us to disentangle competing scattering processes and assess their impact on coherent electronic control. Our panoramic view of field-driven electron motion enables a new quality of microscopic understanding of strong-field control of quantum materials.

DOI: 10.1038/s41586-026-11214-y

Source: https://www.nature.com/articles/s41586-026-11214-y