Magnetic properties of graphene quantum dots

Abstract

Using the tight-binding approximation we calculated the magnetic susceptibility of graphene quantum dots (GQD) of different geometrical shapes and sizes, smaller than the magnetic length, when the magnetic properties are governed by the electron edge states. Two types of edge states can be discerned: the zero-energy states (ZES) located exactly at the zero-energy Dirac point, and the dispersed edge states (DES) with the energy close, but not exactly equal to zero. DES are responsible for the temperature independent diamagnetic response, while ZES provide the temperature dependent spin Curie paramagnetism. The hexagonal, circular and randomly shaped GQDs contain mainly DES and, as a result, they are diamagnetic. The edge states of the triangular GQDs are ZES and these dots reveal the interplay between the spin paramagnetism, dominating for small dots and at low temperatures, and bulk orbital diamagnetism, dominating for large dots and at high temperatures.

References in corpus (16)

• Magnetism in graphene nano-islands
• Electronic transport and quantum Hall effect in bipolar graphene p-n-p junction
• Tuning of energy levels and optical properties of graphene quantum dots
• Metallic Graphene Nanodisks
• Energy levels of triangular and hexagonal graphene quantum dots: a comparative study between the tight-binding and the Dirac approach
• Analytic Model for the Energy Spectrum of a Graphene Quantum Dot in a Perpendicular Magnetic Field
• Anomalous Orbital Magnetism and Hall Effect of Massless Fermions in Two Dimension
• Diamagnetism in disordered graphene
• Electronic structure of triangular, hexagonal and round graphene flakes near the Fermi level
• Orbital magnetism of graphene flakes
• Orbital Magnetism and Transport Phenomena in Two Dimensional Dirac Fermions in Weak Magnetic Field
• Diamagnetism of nodal fermions
• Lattice-Induced Double-Valley Degeneracy Lifting in Magnetic Field in Graphene
• Dirac Fermions in Graphite: the State of Art
• Nonlinear magnetization of graphene
• Orbital magnetic susceptibility of finite-sized graphene

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• Strain induced edge magnetism at zigzag edge in graphene quantum dot
• Electro-absorption of silicene and bilayer graphene quantum dots
• Tuning of Zero Energy States in Quantum Dots of Silicene and Bilayer Graphene by Electric Field
• Graphene quantum blisters: a tunable system to confine charge carriers
• The transfer matrix approach to circular graphene quantum dots
• Tunneling Effect in Gapped Graphene Disk in Magnetic Flux and Electrostatic Potential