Two Studies in Incommensurate Charge Order


Flicker, F. (2016). Two Studies in Incommensurate Charge Order. Perimeter Institute. https://pirsa.org/16100064


Flicker, Felix. Two Studies in Incommensurate Charge Order. Perimeter Institute, Oct. 25, 2016, https://pirsa.org/16100064


          @misc{ pirsa_PIRSA:16100064,
            doi = {10.48660/16100064},
            url = {https://pirsa.org/16100064},
            author = {Flicker, Felix},
            keywords = {Condensed Matter},
            language = {en},
            title = {Two Studies in Incommensurate Charge Order},
            publisher = {Perimeter Institute},
            year = {2016},
            month = {oct},
            note = {PIRSA:16100064 see, \url{https://pirsa.org}}

Felix Flicker University of Bristol

Talk Type Scientific Series


Incommensurate charge order is a phenomenon in which the electrons in a crystal attempt to order with a period irrationally-related to that of

the lattice spacing. In the first half of this talk I will present recent work [1] in which we demonstrate that incommensurately charge-ordered systems can lower their free energy by forming quasicrystals: slices through higher-dimensional crystals with properties lying between  periodicity and disorder. The result potentially greatly increases the number of known, naturally-occuring quasicrystals from the two present examples, both of which were found in the same Siberian meteorite. In the second half I will present work from an ongoing experimental collaboration in which atomically-resolved scanning tunneling microscopy and atomic force microscopy on semiconducting monolayers of molybdenum diselenide (MoSe2) see conducting edge states along one-dimensional mirror twin boundaries. Remarkably, these edge states then develop their own energy gap via charge ordering [2]. We see a number of features suggestive of incommensurate order. By employing a simple analytical model we demonstrate that the effect is in fact a result of fine-tuning between charge ordering and quantum well physics coming from the small system size (on the order of thirty atoms).

[1] F. Flicker and Jasper van Wezel, Physical Review Letters 115, 236401

(2015), Natural 1D Quasicrystals from Incommensurate Charge Order

[2] S. Barja et al., Nature Physics 12, 751-757 (2016), Charge density

wave order in 1D mirror twin boundaries of single-layer MoSe2