Programme

O.1 -- Oral, VCTP-49

Date: Wednesday, 31 July 2024

Time: 17:45 - 18:10

Effects of a perpendicular electric field, electron-hole coupling, and dopants on the electronic phase transition in bilayer P6mmm borophene

Le Thi Thu Phuong (1), Nguyen Ngoc Hieu (2), Huynh Vinh Phuc (3), Vo Thi Tuyet Vi (4), Bui Dinh Hoi (1)

(1) University of Education, Hue University; (2) Duy Tan University; (3) Dong Thap University; (4) University of Medicine and Pharmacy, Hue University

We investigate the influence of external stimuli, including a perpendicular electric field, electron-hole coupling between sublayers (excitonic effects), and dopants on the potential electronic phase transitions in bilayer P6mmm borophene. Our focus is on key electronic properties such as the band structure and density of states. Our findings reveal that the pristine lattice is metal with Dirac cones around the Fermi level, where their intersection forms a nodal line. The system undergoes transitions to a semiconducting state – elimination of nodal line – with a perpendicular electric field and a semimetallic state – transition from two Dirac cones to a single Dirac cone – with combined electric field and excitonic effects. Notably, with these, the system retains its massless Dirac-like bands characteristic at finite energy. However, introducing a dopant still leads to a metallic phase, but the Dirac-like bands become massive. Considering all these effects, the system ultimately reaches a semiconducting phase with massive Dirac-like bands. These results hold significance for optoelectronic applications.

Presenter: Bui Dinh Hoi