The stacking of layered materials into heterostructures offers diverse possibilities for generating deformed Moiré states arising from their mutual interaction. Here we report two-dimensional nanoscale strain networks formed within a single prismatic (H) polytype monolayer of TaS2 created in-situ on the surface of an orthorhombic 1T-TaS2 single crystal by a low-temperature laser-induced polytype transformation. The networks revealed by scanning tunneling microscopy (STM) take on diverse configurations at different temperatures, including extensive double stripes and a twisted 3-gonal mesh of connected 6-pronged vertices.
COBISS.SI-ID: 32649511
Controlled optical or electromagnetic perturbations can lead to an amorphous metastable state of strongly correlated electrons in a quasi-two-dimensional dichalcogenide. Scanning tunnelling microscopy reveals a hyperuniform pattern of localized charges, whereas multitip surface nanoscale conductivity measurements and tunneling spectroscopy show a conducting state that is different from conventional Coulomb glasses and manybody localized systems. The state is stable up to room temperature and shows no signs of either local charge order or phase separation. The mechanism for its formation is attributed to a localization of electrons through mutual interactions. Theoretical calculations confirm the correlations between localized charges to be crucial for the state’s unusual stability.
COBISS.SI-ID: 32539431
The work follows the fundamental idea that the constituents of interacting many body systems in complex quantum materials may self-organize into new and unexpected artificial quantum states. However, in spite of the efforts of a large number of groups worldwide to determine the structure of such matter, and huge recent advances in experimental techniques, demonstrating new emergent order has proven surprisingly difficult. In the work by the group at the Jozef Stefan Institute, the authors use femtosecond-light pulse-induced using scanning tunneling microscopy, reporting for the first time a surprisingly intricate chiral long-range topologically non-trivial charge order emerging in a prototypical two-dimensional material. The discovery of the principles that lead to metastability in charge-ordered systems opens the way to designing novel emergent functionalities, particularly ultrafast all-electronic non-volatile cryo- memories.
COBISS.SI-ID: 32480551