BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Construction and Correlated State Regulation of Graphene Kekulé S uperlattices DTSTART;VALUE=DATE-TIME:20260522T020000Z DTEND;VALUE=DATE-TIME:20260522T030000Z DTSTAMP;VALUE=DATE-TIME:20260524T134700Z UID:indico-event-5029@indico-tdli.sjtu.edu.cn DESCRIPTION:Speakers: Yi Zhang (张翼) (Nanjing University)\n\nHost: Pro f. Hemian Yi  Venue: TDLI Meeting Room N400Tencent Meeting link: https: //meeting.tencent.com/dm/eOQ3rDcnS2bMMeeting ID: 903721257\, no password  Abstract:Constructing novel quantum states via the engineering of various surface/interface superlattices has been a hot topic in condensed matter p hysics in recent years. Taking graphene as a representative example\, the construction of Kekulé distortion with a (√3×√3)R30° superlattice p eriodicity can fold Dirac cones into the Brillouin zone center and open an energy gap. This report will introduce the construction of Kekulé superl attices and the regulation of Dirac fermions in graphene via multiple surf ace/interface element doping strategies.Using angle-resolved photoemission spectroscopy (ARPES)\, we find that disordered impurities on the graphene surface can induce and enhance intervalley elastic scattering of Dirac el ectrons. Below the transition temperature\, mutual interference among scat tered Dirac electrons can form an ordered Kekulé superlattice state\, the reby folding the two inequivalent Dirac cones at the K/K’ points of the Brillouin zone into the zone center [1]. For potassium (K) adsorbed on the surface\, which exhibits heavy electron doping effects\, prominent plasmo ns are generated\, renormalizing the Dirac bands and suppressing the foldi ng of Dirac cones [2]. Gadolinium (Gd) intercalation at the interface of e pitaxial graphene can enhance its surface adsorption capability\, facilita ting the formation of Kekulé periodicity and band folding via nitrogen ad sorption at low temperatures [3]. Ordered europium (Eu) intercalation at t he interface of epitaxial graphene directly forms a Kekulé superlattice. More importantly\, we discover that during band folding process\, the fold ing Dirac fermions in graphene undergo strong exchange coupling with the l ocal magnetic moments of Eu 4f orbital\, inducing significant splitting of the folded Dirac bands [4].This exchange coupling between Dirac electrons and local magnetic moments provides a new degree of freedom for regulatin g Dirac fermions. This giant splitting of folded Dirac bands holds signifi cant scientific importance for advancing the practical applications of Kek ulé graphene in spintronics\, as well as exploring novel quantum states a rising from Dirac electron correlations. References：[1] Can Wang*\, Yi Zhang*\, et al. Nano Letters 21(19)\, 8258-8265 (2021)\;[2] Can Wang*\, Yi Zhang*\, et al. The Journal of Physical Chemistry Letters 13(40)\, 9396-9 403 (2022)\;[3] Can Wang*\, Yi Zhang*\, et al. The Journal of Physical Che mistry Letters 14(32)\, 7149-7156 (2023)\;[4] Xiaodong Qiu\, Can Wang*\, H uaiqiang Wang*\, Yi Zhang*\, et al. The Journal of Physical Chemistry Lett ers 17(10)\, 2785-2791 (2026)\; Biography:Yi Zhang is a Professor at the School of Physics\, Nanjing University. He received his B.S. degree from P eking University in 2006 and earned his Ph.D. from the Institute of Physic s\, Chinese Academy of Sciences\, in 2011. From 2011 to 2015\, he conducte d postdoctoral research at the Lawrence Berkeley National Laboratory and S tanford University\, USA. In 2015\, he joined the School of Physics\, Nanj ing University\, under the National High-Level Overseas Talent Program.His research focuses on molecular beam epitaxy growth of novel two-dimensiona l quantum materials\, as well as the construction and manipulation of emer gent low-dimensional quantum states. To date\, he has published more than 60 peer-reviewed articles with an H-index of 30. He has presided over mult iple national research projects\, including the National Key R&D Program a nd key programs supported by the National Natural Science Foundation of Ch ina. He was listed as an Elsevier Highly Cited Chinese Researcher (2021– 2025) and was selected as a Clarivate Highly Cited Researcher in 2023.\n\n https://indico-tdli.sjtu.edu.cn/event/5029/ LOCATION:Tsung-Dao Lee Institute/N4F-N400 - meeting room (Tsung-Dao Lee In stitute) URL:https://indico-tdli.sjtu.edu.cn/event/5029/ END:VEVENT END:VCALENDAR