Aharonov-Bohm effect and broken valley-degeneracy in graphene rings

Abstract

We analyze theoretically the electronic properties of Aharonov-Bohm rings made of graphene. We show that the combined effect of the ring confinement and applied magnetic flux offers a controllable way to lift the orbital degeneracy originating from the two valleys, even in the absence of intervalley scattering. The phenomenon has observable consequences on the persistent current circulating around the closed graphene ring, as well as on the ring conductance. We explicitly confirm this prediction analytically for a circular ring with a smooth boundary modelled by a space-dependent mass term in the Dirac equation. This model describes rings with zero or weak intervalley scattering so that the valley isospin is a good quantum number. The tunable breaking of the valley degeneracy by the flux allows for the controlled manipulation of valley isospins. We compare our analytical model to another type of ring with strong intervalley scattering. For the latter case, we study a ring of hexagonal form with lattice-terminated zigzag edges numerically. We find for the hexagonal ring that the orbital degeneracy can still be controlled via the flux, similar to the ring with the mass confinement.

7 pages, 7 figures, replaced with considerably extended new version

References in corpus (12)

• Substrate-induced band gap opening in epitaxial graphene
• Valley filter and valley valve in graphene
• Single-shot read-out of an individual electron spin in a quantum dot
• Substrate-induced bandgap in graphene on hexagonal boron nitride
• Electronic States of Graphene Nanoribbons
• Spin qubits in graphene quantum dots
• Weak localisation magnetoresistance and valley symmetry in graphene
• Strong suppression of weak (anti)localization in graphene
• Zeeman energy and spin relaxation in a one-electron quantum dot
• Spin interference effects in ring conductors subject to Rashba coupling
• Detection of valley polarization in graphene by a superconducting contact
• On electron (anti)localization in graphene

Cited by in corpus (130)

• The electronic properties of graphene
• Properties of Graphene: A Theoretical Perspective
• Colloquium: The transport properties of graphene: An introduction
• Topological confinement in bilayer graphene
• Electronic properties of mesoscopic graphene structures: charge confinement and control of spin and charge transport
• Aharonov-Bohm effect in graphene
• AFM local oxidation nanolithography of graphene
• Bound states and magnetic field-induced valley splitting in gate-tunable graphene quantum dots
• Energy levels of triangular and hexagonal graphene quantum dots: a comparative study between the tight-binding and the Dirac approach
• Quantum dots and spin qubits in graphene
• Electrostatic confinement of electrons in an integrable graphene quantum dot
• Spin-orbit interaction and anomalous spin relaxation in carbon nanotube quantum dots
• Character of electronic states in graphene antidot lattices: Flat bands and spatial localization
• Graphene Rings in Magnetic Fields: Aharonov-Bohm Effect and Valley Splitting
• Valley-based noise-resistant quantum computation using Si quantum dots
• Inner and outer edge states in graphene rings: A numerical investigation
• Universal Quantum Computing with Spin and Valley
• Transmission through a boundary between monolayer and bilayer graphene
• Aharonov-Bohm effect in a side-gated graphene ring
• Simplified model for the energy levels of quantum rings in single layer and bilayer graphene
• Conformal mapping and shot noise in graphene
• The Aharonov-Bohm effect in graphene rings
• Bound States of Conical Singularities in Graphene-Based Topological Insulators
• Bound states and persistent currents in topological insulator rings
• Disorder-mediated electron valley resonance in carbon nanotube quantum dots
• Graphene quantum dots for valley-based quantum computing: A feasibility study
• Spin and electronic correlations in gated graphene quantum rings
• Electrostatically confined Quantum Rings in bilayer Graphene
• Interplay of the Aharonov-Bohm effect and Klein tunneling in graphene
• Edge effects in graphene nanostructures: I. From multiple reflection expansion to density of states
• Charge and spin dynamics driven by ultrashort extreme broadband pulses: a theory perspective
• Aharonov-Bohm effect in undoped graphene: Magnetotransport via evanescent waves
• Transition to Landau Levels in Graphene Quantum Dots
• Dirac electrons in graphene-based quantum wires and quantum dots
• Hyperfine-induced valley mixing and the spin-valley blockade in carbon-based quantum dots
• Spin-valley blockade in carbon nanotube double quantum dots
• Aharonov-Bohm effect in an electron-hole graphene ring system
• Valley subband splitting in bilayer graphene quantum point contact
• Mesoscopic rings with Spin-Orbit interactions
• Zero-energy states of graphene triangular quantum dots in a magnetic field
• Control of valley dynamics in silicon quantum dots in the presence of an interface step
• Graphene-based qubits in quantum communications
• Random matrices and quantum chaos in weakly-disordered graphene nanoflakes
• Persistent charge and spin currents in the long wavelength regime for graphene rings
• Currents and pseudomagnetic fields in strained graphene rings
• Persistent currents in Dirac fermion rings
• Effective Magnetic Fields in Graphene Superlattices
• The Berry phase of dislocations in graphene and valley conserving decoherence
• Topological confinement in graphene bilayer quantum rings
• Effective Time Reversal Symmetry Breaking and Energy Spectra of Graphene Armchair Rings
• Chiral separation and chiral magnetic effects in a slab: The role of boundaries
• Light-induced valley currents and magnetization in graphene rings
• Persistent currents in a graphene ring with armchair edges
• Strain-induced transitions to quantum chaos and effective time-reversal symmetry breaking in triangular graphene nanoflakes
• Josephson effect in Graphene SNS Junction with a Single Localized Defect
• Aharonov-Bohm interferometer based on n-p junction in graphene nanoribbons
• Geometric phases and the Sagnac effect: Foundational aspects and sensing applications
• Patterns of the Aharonov-Bohm oscillations in graphene nanorings
• Terahertz Transverse-Electric- and Transverse-Magnetic-polarized waves localized on graphene in photonic crystals
• Quantum oscillation and wave packet revival in conical graphene structure
• Photoexcitation of graphene with twisted light
• Magnetic scattering of Dirac fermions in topological insulators and graphene
• Aharonov-Bohm effect and giant magnetoresistance in graphene nanoribbon rings
• Topological effects and particle-physics analogies beyond the massless Dirac-Weyl fermion in graphene nanorings
• Gate-Tunable Graphene Quantum Dot and Dirac Oscillator
• Lorentz force effects for graphene Aharonov-Bohm interferometers
• Fermionic vacuum currents in topologically nontrivial braneworlds: Two-brane geometry
• Resonant scattering in graphene with a gate-defined chaotic quantum dot
• Transmission of phase information between electrons and holes in graphene
• Fano resonances in hexagonal zigzag graphene rings under external magnetic flux
• Quasi-energy spectra of graphene dots under intense ac field: field anisotropy and photon dressed quantum rings
• Magnetic edge states in Aharonov-Bohm graphene quantum rings
• The Casimir effect for fermionic currents in conical rings with applications to graphene ribbons
• Quantum oscillations as a probe of interaction effects in Weyl semimetals in a magnetic field
• Transport, Aharonov-Bohm, and Topological Effects in Graphene Molecular Junctions and Graphene Nanorings
• Tunneling Conductance of The Graphene SNS Junction with a Single Localized Defect
• Electrons trapped in graphene magnetic quantum dots with mass term
• Suppression of decoherence in a graphene monolayer ring
• The Chiral Qubit: quantum computing with chiral anomaly
• Valley relaxation in graphene due to charged impurities
• Induced fermionic charge and current densities in two-dimensional rings
• Induced current in the presence of magnetic flux tube of small radius
• Mass-profile quantum dots in graphene
• Imaging Electron Motion in Graphene
• Isolated and hybrid bilayer graphene rings
• Valley properties of doped graphene in a magnetic field
• Scars in Dirac fermion systems: the influence of an Aharonov--Bohm flux
• Orbital Magnetism of Graphene Nanostructures: Bulk and Confinement Effects
• Polarized light bursts from kicked quantum rings
• Effect of magnetic field on the electronic properties of an $\alpha$-$T_3$ ring
• Dirac electrons in quantum rings
• Relativistic fermion on a ring: Energy spectrum and persistent current
• Aharonov-Bohm conductance oscillations and current equilibration in local n - p junctions in graphene
• Spin and valley manipulation in single and double electrostatic silicene quantum dots
• Finite temperature fermionic condensate in a conical space with a circular boundary and magnetic flux
• Persistent current of relativistic electrons on a Dirac ring in presence of impurities
• Topologically protected wave packets and quantum rings in silicene
• Graphene flakes with defective edge terminations: Universal and topological aspects, and one-dimensional quantum behavior
• Theory of spin qubits in nanostructures
• Electron trapping in graphene quantum dots with magnetic flux
• Anomalous Valley Magnetic Moment of Graphene
• Spin-active devices based on graphene / WSe${}_2$ heterostructure
• Valley-resolved Fano resonance in monolayer transition metal dichalcogenides nanoribbons with attached stubs
• Aharonov-Bohm effect with an effective complex-valued vector potential
• Chiral properties of topological-state loops
• Seeking Maxwell's Demon in a non-reciprocal quantum ring
• Orbital hyperfine interaction and qubit dephasing in carbon nanotube quantum dots
• Topological bound states for quantum charges
• Trigonal warping, pseudodiffusive transport, and finite-system version of the Lifshitz transition in magnetoconductance of bilayer-graphene Corbino disks
• Electronic Properties of Graphene Quantum Ring with Wedge Disclination
• Geometry effects in topologically confined bilayer graphene loops
• Transport and quantum coherence in graphene rings: Aharonov-Bohm oscillations, Klein tunneling and particle localization
• Tunable circular dipolelike system in graphene: Mixed electron-hole states
• Persistent currents in absence of magnetic field in graphene nanorings: The ambiguous role of inter valley scattering
• Magnetic forces in the absence of a classical magnetic field
• Persistent currents in topological and trivial confinement in silicene
• Perfect valley polarization in MoS2
• Finite temperature fermionic charge and current densities in conical space with a circular edge
• Low-energy trions in graphene quantum dots
• Aharonov-Bohm-Coulomb Problem in Graphene Ring
• Electronic properties of bilayer graphene with magnetic quantum structures studied using the Dirac equation
• Four-band effective square lattice model for Bernal-stacked bilayer graphene
• Aharonov-Casher effect and quantum transport in graphene based nano rings: A self-consistent Born approximation
• Strain-induced Aharonov-Bohm effect at nanoscale and ground state of a carbon nanotube with zigzag edges
• Mach--Zehnder-like interferometry with graphene nanoribbon networks
• Josephson Current in Ballistic Graphene Corbino Disk
• Aharonov-Bohm and relativistic Corbino effects in graphene: A comparative study of two quantum interference phenomena
• Magnetic control of electron scattering in silicene quantum dots
• The Aharonov-Bohm effect for massless Dirac fermions and the spectral flow of Dirac type operators with classical boundary conditions
• Electronic states in quantum wires on a Möbius strip