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Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
Published on: July 24, 2015
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Graphene levitons and anti-levitons in magnetic fields.
Derek Michael Forrester1, Feodor V Kusmartsev
1Department of Physics, School of Science, Loughborough University, Leicestershire, UK. d.m.forrester@lboro.ac.uk.
Nanoscale
|June 5, 2014
Summary
Researchers explored levitons, electron wavepackets in graphene, and their unique behaviors under pulsed excitations. They discovered magnetic fields can control Klein tunneling and lead to novel excitations like levity vortices.
Area of Science:
- Condensed Matter Physics
- Quantum Mechanics
- Materials Science
Background:
- Levitons are soliton-like electron or hole wavepackets on the Fermi sea surface.
- Graphene's unique Dirac point Fermi surface offers novel leviton characteristics.
- Previous studies have explored basic leviton formation and behavior.
Purpose of the Study:
- Investigate leviton formation and dynamics in graphene under pulsed excitations.
- Analyze the influence of external magnetic fields on leviton behavior, including Klein tunneling and refraction.
- Characterize new elementary excitations, such as the levity vortex.
Main Methods:
- Theoretical modeling of electron wavepackets in graphene.
- Simulation of time-dependent pulse excitations (Lorentzian, Gaussian).
- Analysis of quantum transport phenomena under weak and moderate magnetic fields.
Main Results:
- Leviton formation is observed, associated with chiral anomalies and anti-leviton formation at potential steps.
- Weak magnetic fields can modulate leviton Klein tunneling.
- Moderate fields induce negative refraction; stronger fields create levity vortices in reflected wavefunctions.
Conclusions:
- Graphene provides a unique platform for studying complex leviton dynamics.
- External magnetic fields offer control over leviton transport and can lead to novel quantum phenomena.
- The study introduces the levity vortex as a new elementary excitation in reflected wavefunctions.
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