# Position and momentum mapping of vibrations in graphene nanostructures

@article{Senga2019PositionAM, title={Position and momentum mapping of vibrations in graphene nanostructures}, author={Ryosuke Senga and Kazu Suenaga and Paolo Barone and Shigeyuki Morishita and Francesco Mauri and T. Pichler}, journal={Nature}, year={2019}, pages={1-4} }

Propagating atomic vibrational waves—phonons—determine important thermal, mechanical, optoelectronic and transport characteristics of materials. Thus a knowledge of phonon dispersion (that is, the dependence of vibrational energy on momentum) is a key part of our understanding and optimization of a material’s behaviour. However, the phonon dispersion of a free-standing monolayer of a two-dimensional material such as graphene, and its local variations, have remained elusive for the past decade…

## 57 Citations

### Four-dimensional vibrational spectroscopy for nanoscale mapping of phonon dispersion in BN nanotubes

- PhysicsNature communications
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A four-dimensional electron energy loss spectroscopy technique is demonstrated, and position-dependent phonon dispersion measurements in individual boron nitride nanotubes are presented, revealing position- and momentum-dependent lattice vibrations at nanometer scale.

### Tailored Nanoscale Plasmon-Enhanced Vibrational Electron Spectroscopy

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It is experimentally demonstrated that the interaction between a relativistic electron and vibrational modes in nanostructures is fundamentally modified in the presence of plasmons, holding great potential for investigating sensing mechanisms and chemistry in complex nanomaterials down to the molecular level.

### Single-defect phonons imaged by electron microscopy

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- 2021

The capabilities of a state-of-the-art transmission electron microscope open the door to the direct mapping of phonon propagation around defects, which is expected to provide useful guidance for engineering the thermal properties of materials.

### Vibrational STEM-EELS of Single Si Atom Point Defects in Graphene

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- 2020

Electron energy loss spectroscopy (EELS) in state-of-the-art monochromated scanning transmission electron microscopes (STEMs) allows for probing the vibrational response of a wide range of materials…

### Three dimensional vectorial imaging of surface phonons.

- Physics
- 2020

While phonons and their related properties have been studied comprehensively in bulk materials, a thorough understanding of surface phonons for nanoscale objects remains elusive. Infra-red imaging…

### Simultaneous excitation of phonons at the center and boundaries of Brillouin zones with high energy electron beams

- Physics
- 2020

High energy electron beams can now be routinely focused to 1-2 A and offer the ability to obtain vibrational information from materials using monochromated electron energy-loss spectroscopy (EELS) in…

### Simulations of spatially and angle-resolved vibrational electron energy loss spectroscopy for a system with a planar defect

- PhysicsPhysical Review B
- 2021

Recent developments in experiments with vibrational electron energy loss spectroscopy (EELS) have revealed spectral shape variations at spatial resolutions down to sub-atomic scale. Interpretation in…

### Measuring phonon dispersion at an interface.

- PhysicsNature
- 2021

The four-dimensional electron energy-loss spectroscopy technique is used to directly measure both the local vibrational spectra and the interface phonon dispersion relation for an epitaxial cubic boron nitride/diamond heterointerface to provide insights into lattice dynamics at heterointerfaces.

### Direct observation of highly confined phonon polaritons in suspended monolayer hexagonal boron nitride

- PhysicsNature Materials
- 2020

Monochromatic electron energy-loss spectroscopy enables the observation of highly confined and ultraslow hyperbolic phonon polaritons in suspended monolayer hexagonal boron nitride, expanding the potential of van der Waals materials for nanophotonic applications.

### Role of Convergence and Collection Angles in the Excitation of Long- and Short-Wavelength Phonons with Vibrational Electron Energy-Loss Spectroscopy

- PhysicsMicroscopy and Microanalysis
- 2021

In crystals, long- and short-wavelength phonon modes can be probed simultaneously with on-axis vibrational STEM EELS to help develop a fundamental connection between vibrational excitations and bonding arrangements at atomic-scale heterogeneities in materials.

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