Static electric field enhancement in nanoscale structures

Lepetit, Bruno; Lemoine, Didier; Márquez-Mijares, Maykel

doi:10.1063/1.4961216

Cited by 20 publications

(15 citation statements)

References 46 publications

(49 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Note that a previous study showed that local field variation for an atomically sharp step edge is only a factor of around 2, not much greater. 39 Hence all the observations and simulations coherently support the presence of a nano-tip at a corner of the surface facets with the well pronounced surrounding steps.…”

confidence: 61%

Laser-induced asymmetric faceting and growth of a nano-protrusion on a tungsten tip

et al. 2016

View full text Add to dashboard Cite

Irradiation of a sharp tungsten tip by a femtosecond laser and exposed to a strong DC electric field led to gradual and reproducible surface modifications. By a combination of field emission microscopy and scanning electron microscopy, we observed asymmetric surface faceting with sub-ten nanometer high steps. The presence of well pronounced faceted features mainly on the laser-exposed side implies that the surface modification was driven by a laser-induced transient temperature rise -on a scale of a couple of picoseconds -in the tungsten tip apex. Moreover, we identified the formation of a nano-tip a few nanometers high located at one of the corners of a faceted plateau. The results of simulations emulating the experimental conditions, are consistent with the experimental observations. The presented conditions can be used as a new method to fabricate nano-tips of few nm height, which can be used in coherent electron pulses generation. Besides the direct practical application, the results also provide insight into the microscopic mechanisms of light-matter interaction. The apparent growth mechanism of the features may also help to explain the origin of enhanced electron field emission, which leads to vacuum arcs, in high electric-field devices such as radio-frequency particle accelerators.A metallic nano-tip with sharpness of a few nanometers can provide very bright and spatially coherent electron waves. [1][2][3][4][5] This is highly beneficial in many applications such as electron diffraction, microscopy, and holography. [6][7][8] During irradiation by laser pulses a nanotip is also expected to generate pulsed electron waves with high brightness and coherence. [9][10][11][12][13] Such electron pulses enable experiments with high temporal and spatial resolution for investigations of ultrafast phenomena in solids. 14 A higher-performance pulsed electron source could make a significant contribution to future investigations of the dynamics in ultrafast devices. 15 So far various well-established methods have been used to fabricate nano-tips. [1][2][3][4][16][17][18] Typically, a nano-tip is grown on a larger metallic tip by applying strong DC fields, [2][3][4][16][17][18] heating 3,16-18 or depositing metal. 1,4 Fabrication of a nano-tip in situ for laser-induced elec-

show abstract

confidence: 61%

Laser-induced asymmetric faceting and growth of a nano-protrusion on a tungsten tip

et al. 2016

View full text Add to dashboard Cite

show abstract

“…34,35) available to adress the problem of field emission from materials. We propose here to extend to the present 2D materials the use of the perturbative methods developped recently [36][37][38] to describe emission from metals. We present a time-independent variant of our original timedependent method using the Bardeen transfer Hamiltonian formalism 39 .…”

Section: Introductionmentioning

confidence: 99%

A quantum mechanical model of electron field emission from two dimensional materials. Application to graphene

Lepetit

2021

Journal of Applied Physics

Self Cite

View full text Add to dashboard Cite

We implement a new time-independent perturbative quantum method to study quantitatively electron field emission from two dimensional materials and in particular from graphene. The Bardeen transfer Hamiltonian formalism is coupled to a detailed description of the electronic structure of the material. This calculation method is first validated on the standard Fowler-Nordheim (FN) model of a 3 dimensional (3D) free electron gas. Then, it is used to study emission from a 2 dimensional (2D) free electron gas and from graphene represented by a tight-binding model. In the case of graphene, we show that a full electronic band model of the material is necessary to obtain reasonable results because emission is not restricted to the vicinity of the Fermi level near the Dirac points. The graphene emitted current density follows a modified FN law with respect to the applied field, with a prefactor exponent for the field n ≈ 1.5 intermediate between the one for the cases of 2D (n = 0) and 3D (n = 2) free electron gases. However, the emitted current level is low because the kinetic energy of the electrons corresponds to a motion parallel to the emitting surface which is not efficient in promoting emission. Our study gives a firm ground to the idea that emission from graphene results almost exclusively from defects.

show abstract

“…In the present context of field emission, the external field is orders of magnitude smaller than the intrisic electrostatic field (i.e. the one experienced by the electrons of the material without external field), in particular in the vicinity of the material/vacuum interface 18 . It is therefore reasonable to study the effect of the external field on electronic emission using perturbation theory.…”

Section: Time Independent Perturbative Modelsmentioning

confidence: 91%

“…We use this program in a way very similar to the one already described in refs. 16,18. The electron-ion interaction for tungsten is described by the projector augmented wave potential (PAW) 55,56 .…”

Section: Numerical Implementation a Potential Energies And Statesmentioning

confidence: 99%

See 1 more Smart Citation

Electronic field emission models beyond the Fowler-Nordheim one

Lepetit

2017

Journal of Applied Physics

Self Cite

View full text Add to dashboard Cite

We propose several quantum mechanical models to describe electronic field emission from first principles. These models allow to correlate quantitatively the electronic emission current to the electrode surface details at the atomic scale. They all rely on electronic potential energie surfaces obtained from three dimensional density functional theory calculations. They differ by the various quantum mechanical methods (exact or perturbative, time dependent or time independent) which are used to describe tunneling through the electronic potential energy barrier. Comparison of these models between them and with the standard Fowler-Nordheim one in the context of one dimensional tunneling allows to assess the impact on the accuracy of the computed current of the approximations made in each model. Among these methods, the time dependent perturbative one provides a well balanced trade-off between accuracy and computational cost.

show abstract

Static electric field enhancement in nanoscale structures

Cited by 20 publications

References 46 publications

Laser-induced asymmetric faceting and growth of a nano-protrusion on a tungsten tip

Laser-induced asymmetric faceting and growth of a nano-protrusion on a tungsten tip

A quantum mechanical model of electron field emission from two dimensional materials. Application to graphene

Electronic field emission models beyond the Fowler-Nordheim one

Contact Info

Product

Resources

About