| Autor: |
Pekka, Koskinen, Ioanna, Fampiou, Ashwin, Ramasubramaniam |
| Rok vydání: |
2013 |
| Zdroj: |
Physical review letters. 112(18) |
| ISSN: |
1079-7114 |
| Popis: |
Monolayer transition-metal dichalcogenides (TMDCs) display valley-selective circular dichroism due to the presence of time-reversal symmetry and the absence of inversion symmetry, making them promising candidates for valleytronics. In contrast, in bilayer TMDCs both symmetries are present and these desirable valley-selective properties are lost. Here, by using density-functional tight-binding electronic structure simulations and revised periodic boundary conditions, we show that bending of bilayer MoS2 sheets breaks band degeneracies and localizes states on separate layers due to bending-induced strain gradients across the sheets. We propose a strategy for employing bending deformations in bilayer TMDCs as a simple yet effective means of dynamically and reversibly tuning their band gaps while simultaneously tuning valley-selective physics. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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