skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Suppression of decoherence in a graphene monolayer ring

Abstract

The influence of high magnetic fields on coherent transport is investigated. A monolayer graphene quantum ring is fabricated and the Aharonov-Bohm effect is observed. For increased magnitude of the magnetic field, higher harmonics appear. This phenomenon is attributed to an increase of the phase coherence length due to reduction of spin flip scattering.

Authors:
; ;  [1]
  1. Institut für Festkörperphysik, Leibniz Universität Hannover, Appelstr. 2, 30167 Hannover (Germany)
Publication Date:
OSTI Identifier:
22310954
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 8; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; AHARONOV-BOHM EFFECT; COHERENCE LENGTH; GRAPHENE; HARMONICS; MAGNETIC FIELDS; QUANTUM DECOHERENCE; REDUCTION; RINGS; SCATTERING; SPIN FLIP

Citation Formats

Smirnov, D., E-mail: smirnov@nano.uni-hannover.de, Rode, J. C., and Haug, R. J. Suppression of decoherence in a graphene monolayer ring. United States: N. p., 2014. Web. doi:10.1063/1.4894471.
Smirnov, D., E-mail: smirnov@nano.uni-hannover.de, Rode, J. C., & Haug, R. J. Suppression of decoherence in a graphene monolayer ring. United States. doi:10.1063/1.4894471.
Smirnov, D., E-mail: smirnov@nano.uni-hannover.de, Rode, J. C., and Haug, R. J. Mon . "Suppression of decoherence in a graphene monolayer ring". United States. doi:10.1063/1.4894471.
@article{osti_22310954,
title = {Suppression of decoherence in a graphene monolayer ring},
author = {Smirnov, D., E-mail: smirnov@nano.uni-hannover.de and Rode, J. C. and Haug, R. J.},
abstractNote = {The influence of high magnetic fields on coherent transport is investigated. A monolayer graphene quantum ring is fabricated and the Aharonov-Bohm effect is observed. For increased magnitude of the magnetic field, higher harmonics appear. This phenomenon is attributed to an increase of the phase coherence length due to reduction of spin flip scattering.},
doi = {10.1063/1.4894471},
journal = {Applied Physics Letters},
number = 8,
volume = 105,
place = {United States},
year = {Mon Aug 25 00:00:00 EDT 2014},
month = {Mon Aug 25 00:00:00 EDT 2014}
}
  • Synthesis of bilayer graphene by chemical vapor deposition is of importance for graphene-based field effect devices. Here, we demonstrate that bilayer graphene preferentially grows by carbon-segregation under graphene sheets that are rotated relative to a Ni(111) substrate. Rotated graphene monolayer films can be synthesized at growth temperatures above 650 C on a Ni(111) thin-film. The segregated second graphene layer is in registry with the Ni(111) substrate and this suppresses further C-segregation, effectively self-limiting graphene formation to two layers.
  • In this paper, we show that a graphene quantum disk (GQD) can be generated on monolayer graphene via structural modification using the electron beam. The electronic structure and local optical responses of the GQD, supported on monolayer graphene, were probed with electron energy-loss spectrum imaging on an aberration-corrected scanning transmission electron microscope. We observe that for small GQD, {approx}1.3 nm in diameter, the electronic structure and optical response are governed by the dominating edge states, and are distinctly different from either monolayer graphene or double-layer graphene. Highly localized plasmon modes are generated at the GQD due to the confinement frommore » the edge of the GQD in all directions. The highly localized optical response from GQDs could find use in designing nanoscale optoelectronic and plasmonic devices based on monolayer graphene.« less
  • We have formulated a transfer matrix method to investigate electronic properties of graphene heterostructure consisting of monolayer graphene and bilayer counterpart. By evaluating transmission, conductance, and band dispersion, we show that, irrespective of the different carrier chiralities in monolayer graphene and bilayer graphene, superlattice consisting of biased bilayer graphene barrier and monolayer graphene well can mimic the electronic properties of conventional semiconductor superlattice, displaying the extended subbands in the quantum tunneling regime and producing anisotropic minigaps for the classically allowed transport. Due to the lateral confinement, the lowest mode has shifted away from the charge neutral point of monolayer graphenemore » component, opening a sizeable gap in concerned structure. Following the gate-field and geometry modulation, all electronic states and gaps between them can be externally engineered in an electric-controllable strategy.« less
  • No abstract prepared.