Bound states and magnetic field-induced valley splitting in gate-tunable graphene quantum dots

Details Bound states and magnetic field-induced valley splitting in gate-tunable graphene quantum dots Bound states and magnetic field-induced valley splitting in gate-tunable graphene quantum dots

2008-10-02

arxiv.org/abs/0810.0419v1

Phys. Rev. B 79, 085407 (2009)

Physics

Condensed Matter

Mesoscale and Nanoscale Physics

12 pages, 10 figures

Scientific paper

10.1103/PhysRevB.79.085407

The magnetic field dependence of energy levels in gapped single- and bilayer graphene quantum dots (QDs) defined by electrostatic gates is studied analytically in terms of the Dirac equation. Due to the absence of sharp edges in these types of QDs, the valley degree of freedom is a good quantum number. We show that its degeneracy is efficiently and controllably broken by a magnetic field applied perpendicular to the graphene plane. This opens up a feasible route to create well-defined and well controlled spin- and valley-qubits in graphene QDs. We also point out the similarities and differences in the spectrum between single- and bilayer graphene quantum dots. Striking in the case of bilayer graphene is the anomalous bulk Landau level (LL) that crosses the gap which results in crossings of QD states with this bulk LL at large magnetic fields in stark contrast to the single-layer case where this LL is absent. The tunability of the gap in the bilayer case allows us to observe different regimes of level spacings directly related to the formation of a pronounced ``Mexican hat'' in the bulk bandstructure. We discuss the applicability of such QDs to control and measure the valley isospin and their potential use for hosting and controlling spin qubits.

Affiliated with

Also associated with

No associations

Rating

Bound states and magnetic field-induced valley splitting in gate-tunable graphene quantum dots does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Bound states and magnetic field-induced valley splitting in gate-tunable graphene quantum dots, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bound states and magnetic field-induced valley splitting in gate-tunable graphene quantum dots will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-492467