Dresden 2026 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 4: Graphene, 2D and Twisted Materials

TT 4.1: Vortrag

Montag, 9. März 2026, 09:30–09:45, HSZ/0105

Toward electron lensing in graphene — Yi-Chen Tsai^1,2, Yu-En Wu³, Chung-Ting Ke^2,4, and •Ming-Hao Liu³ — ¹Institute of Physics, Academia Sinica, Taipei, Taiwan — ²Department of Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan — ³Department of Physics and Center for Quantum Frontiers of Research and Technology (QFort), National Cheng Kung University, Tainan, Taiwan — ⁴Research Center for Critical Issues, Academia Sinica, Tainan, Taiwan

Electron lensing in graphene based on the combined effects of Klein collimation and negative refraction was theoretically proposed in [1]. The proposal promises striking phenomena that could advance the emerging field of electron optics in graphene. Yet, the original design requiring a parabolic pn junction and a point-like injector at the focal point has remained experimentally demanding and unverified. Here, we present recent progress toward realizing electron lensing in state-of-the-art ultraclean graphene devices. These devices feature multiple contacts—point injectors, narrow collectors, and wide drains—engineered to probe the lensing regime. Low-temperature transport measurements are systematically compared with fully ballistic quantum transport simulations at zero temperature. This combined experimental-theoretical approach enables us to assess how closely current devices approach the envisioned lensing regime described in [1] and to identify critical steps still needed for its experimental confirmation.

[1] M.-H. Liu, C. Gorini, and K. Richter, PRL 118, 066801 (2017).

Keywords: quantum transport; electron optics; graphene