Dresden 2026 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 49: Correlated Electrons: Charge Order
TT 49.6: Talk
Wednesday, March 11, 2026, 12:00–12:15, HSZ/0101
Doping-tunable charge ordering in semiconducting single-layer Cr2Se3 — •Sisheng Duan and Miguel Ugeda — Donostia International Physics Center, Paseo Manuel de Lardizábal 4, 20018 San Sebastián, Spain
The charge density wave (CDW), a charge ordering phase, offers a valuable framework for exploring electron-electron interactions, electron-phonon coupling, and quantum phase transitions. In CDW materials, carrier density substantially influences the ground state, typically altered through foreign ion doping and investigated at macro- or mesoscopic scales via photoemission or transport techniques. However, atomic-scale visualization, particularly in doped CDW systems without foreign ions, remains rare. Here, we present real-space observation of doping-tunable granular charge ordering using scanning tunneling microscopy in semiconducting single-layer Cr2Se3, a group VIB transition metal chalcogenide. Observations of lattice distortion, bandgap modulation at the Fermi energy, and STM contrast inversion at low temperatures indicate a charge ordering origin. The semiconducting nature of Cr2Se3 enables charge ordering modulation through doping: Hole doping suppresses it, whereas electron doping alters the pattern, yielding a periodic 3√3 × 3√3 CDW phase. This tunable charge ordering in a group VIB TMC advances the understanding of charge doping and ordering interactions in two-dimensional materials.
Keywords: scanning tunneling microscopy; molecular beam epitaxy; charge density wave; two-dimensional materials; transitional metal chalcogenide