| AVS 63rd International Symposium & Exhibition | |
| 2D Materials Focus Topic | Tuesday Sessions |
| Session 2D+MI-TuM |
| Session: | Novel 2D Materials |
| Presenter: | Yoshi Iwasa, University of Tokyo, Japan |
| Correspondent: | Click to Email |
Scaling down materials to an atomic-layer level produces rich physical and chemical properties as exemplified in various two-dimensional (2D) crystals extending from graphene, transition metal dichalcogenidesto black phosphorous. These include Dirac physics, quantum Hall physics, and valleytronic functions, which are caused by the dramatic modification of electronic band structures, simply by thinning. In the case of transition metal dichalcogenides (TMDs), the band gap becomes direct in monolayers, and the broken inversion symmetry and the strong spin-orbit interaction causes peculiar valley-dependent spin polarization in zero-magnetic field [1], as well as peculiar opto-valleytronics [2, 3].
In reduced dimensions, on the other hand, the electron correlation effects and their consequence, electronic phase transitions, are also significantly changed from bulk systems, and thus result in new properties and functions. Here we address unique physical properties of correlated 2D electron system 1T-TaS2, which was achieved simply by thinning. The ordering kinetics of the charge density wave transition was revealed to become extremely slow with reduction of thickness [4], resulting in an emergence of metastable states [5]. Furthermore, we realized the unprecedented memristive switching to multi-step non-volatile states by applying in-plane electric field.
[1] R. Suzuki et al, Nat. Nano. 9, 611 (2014).
[2] Y. J. Zhang et al., Nano Lett. 12, 1136 (2012), ibid. 13, 3023 (2013).
[3] Y. J. Zhang et al., Science 344, 725 (2014).
[4] M. Yoshida et al., Sci. Rep. 4, 7302 (2014).
[5] M. Yoshida et al., Sci. Adv. 1, e1500606 (2015).