2016/02/16 by Achintya Bera, Koushik Pal, D V S Muthu +2
Materials Science · Physics and Astronomy · #2D Materials and Applications #Advanced Thermoelectric Materials and Devices #Electronic structure #Hydrostatic pressure #Isostructural #Phase transition #Quantum phase transition #Raman spectroscopy #Selenide #Topological Materials and Phenomena #Topological insulator #Topology (electrical circuits) #cond-mat.mtrl-sci
paper · pdf · doi:10.1088/0953-8984/28/10/105401
published as J. Phys.: Condens. Matter 28 (2016) 105401 (8pp) · 18 pages , 6 figures
openalex publication_date 2016/02/16 · arxiv created 2016/02/18 · arxiv updated 2016/03/23 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
In recent years, a low pressure transition around P3 GPa exhibited by the A2B3-type 3D topological insulators is attributed to an electronic topological transition (ETT) for which there is no direct evidence either from theory or experiments. We address this phase transition and other transitions at higher pressure in bismuth selenide (Bi2Se3) using Raman spectroscopy at pressure up to 26.2 GPa. We see clear Raman signatures of an isostructural phase transition at P2.4 GPa followed by structural transitions at ∼ 10 GPa and 16 GPa. First-principles calculations reveal anomalously sharp changes in the structural parameters like the internal angle of the rhombohedral unit cell with a minimum in the c/a ratio near P3 GPa. While our calculations reveal the associated anomalies in vibrational frequencies and electronic bandgap, the calculated Z2 invariant and Dirac conical surface electronic structure remain unchanged, showing that there is no change in the electronic topology at the lowest pressure transition.