Regensburg 2022 – wissenschaftliches Programm

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

HL: Fachverband Halbleiterphysik

HL 11: 2D Materials 2 (joint session HL/CPP/DS)

HL 11.12: Vortrag

Montag, 5. September 2022, 18:15–18:30, H36

Strain control of spins in monolayer WSe₂ — •Abhijeet Kumar¹, Douglas J. Bock¹, Pablo Hernández López², Sebastian Heeg², Christoph Schattauer³, Florian Libisch³, Bianca Höfer¹, Cornelius Gahl¹, and Kirill I. Bolotin¹ — ¹Freie Universität Berlin, Arnimalle 14, 14195, Berlin, Germany — ²Institut für Physik und IRIS Adlershof, Humboldt Universität zu Berlin, 12489 Berlin, Germany — ³Vienna University of Technology, Austria

Mechanical strain controls band hierarchy and excitons in the transition metal dichalcogenides (TMDs). Here, we apply remarkably large biaxial strain exceeding 2% in a suspended 1L-WSe₂ at cryogenic temperatures and unveil novel strain responses. First, the conduction bands hybridize with the in-gap localized defects under 1% strain that breaks spin-valley locking. Second, we show that the defects are critical for valley physics as we observe near 100% loss of exciton valley coherence under hybridization. At the same time, the associated defects and dark states gain up to 400% valley polarization. Finally, we show ultrafast strain control of spins and charges in a suspended WSe₂ device. Our observations may play a critical role in the applications of TMDs in strain-valleytronics.