| Autor: |
Sim S; Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea. mj.han@kaist.ac.kr., Jeong MY; Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea. mj.han@kaist.ac.kr., Lee H; Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea. mj.han@kaist.ac.kr., Lee DHD; Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea. mj.han@kaist.ac.kr., Han MJ; Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea. mj.han@kaist.ac.kr. |
| Abstrakt: |
To understand the alkali-metal-dependent material properties of recently discovered AV 3 Sb 5 (A = K, Rb, and Cs), we conducted a detailed electronic structure analysis based on first-principles density functional theory calculations. Contrary to the case of A = K and Rb, the energetic positions of the low-lying Van Hove singularities are reversed in CsV 3 Sb 5 , and the characteristic higher-order Van Hove point gets closer to the Fermi level. We found that this notable difference can be attributed to the chemical effect, apart from structural differences. Due to their different orbital compositions, Van Hove points show qualitatively different responses to the structure changes. A previously unnoticed highest lying point can be lowered, locating close to or even below the other ones in response to a reasonable range of bi- and uni-axial strain. Our results can be useful in better understanding the material-dependent features reported in this family and in realizing experimental control of exotic quantum phases. |
