Observation of orbital order in the Van der Waals material 1T-TiSe2

Yingying Peng, ∗ Xuefei Guo, Qian Xiao, Qizhi Li, Jörg Strempfer, Yongseong Choi, Dong Yan, 5 Huixia Luo, Yuqing Huang, Shuang Jia, Oleg Janson, Peter Abbamonte, Jeroen van den Brink, 7, 8 and Jasper van Wezel † International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China Department of Physics and Materials Research Laboratory, University of Illinois, Urbana, IL 61801, USA Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA School of Materials Science and Engineering, State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275, China Key Laboratory of Functional Molecular Solids, Ministry of Education, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241002, China Institute for Theoretical Solid State Physics, IFW Dresden, Helmholtzstr. 20, 01069 Dresden, Germany Würzburg-Dresden Cluster of Excellence ct.qmat, TU Dresden, 01069 Dresden, Germany Institute for Theoretical Physics Amsterdam, University of Amsterdam, Science Park904, 1098 XH Amsterdam, The Netherlands (Dated: May 28, 2021)