Electric Field Effects on Curved Graphene Quantum Dots

Abstract

The recent and continuous research on graphene-based systems has opened their usage to a wide range of applications due to their exotic properties. In this paper, we have studied the effects of an electric field on curved graphene nanoflakes, employing the Density Functional Theory. Both mechanical and electronic analyses of the system have been made through its curvature energy, dipolar moment, and quantum regeneration times, with the intensity and direction of a perpendicular electric field and flake curvature as parameters. A stabilisation of non-planar geometries has been observed, as well as opposite behaviours for both classical and revival times with respect to the direction of the external field. Our results show that it is possible to modify regeneration times using curvature and electric fields at the same time. This fine control in regeneration times could allow for the study of new phenomena on graphene.

Asymmetric electronic deformation in graphene molecular capacitors

“…Since charging process of molecular capacitors is utilized via electric field vector perpendicular to molecular sheets, the electric field vector for the present work is also applied perpendicular to the graphene flakes' sheets, in which $$$ E=V/R $$$ relates magnitude of electric field ($$$ E $$$) to voltage ($$$ V $$$), where $$$ R $$$ is the interflake distance. In general, electric field removes planarity of graphene flakes depending on its strength [80–83]. Figure 5 depicts side views of slightly bent optimized structures of single graphene flakes exposed to electric field perpendicular to the flake's plane corresponding to 4 V for 3.5 Å separation distance between parallel flakes, under no geometrical constrain for planarity of the flakes.…”

Quantum revivals in HgTe/CdTe quantum wells and topological phase transitions

“…This event occurs periodically and the period is known as the revival period. The phenomenon of quantum wave packet revivals has been investigated theoretically in atomic systems, molecules, many body systems or 2D Materials [1][2][3][4][5][6][7][8][9][10][11] and observed experimentally in among others, Rydberg atoms or molecular systems [12][13][14][15][16]. Recently, it has been shown how revival and classical periods reveal quantum phase transitions in many-body systems [5,6].…”