Orientation-Dependent Multiphoton Ionization in Wide Band Gap Crystals

Gertsvolf, Marina; Jean-Ruel, Hubert; Rajeev, P. P.; Klug, D. D.; Rayner, D. M.; Corkum, P. B.

doi:10.1103/physrevlett.101.243001

Cited by 73 publications

(56 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, our measurements support the finding of McFarland et al (10)that tunneling from a lower-lying orbital can dominate the high harmonic spectrum for certain molecular alignments. Our results further imply that attosecond hole dynamics resulting from tunneling will be ubiquitous in atoms and molecules (11)a sw e l la si ns o l i d s ( 14).…”

mentioning

confidence: 88%

See 1 more Smart Citation

Laser Tunnel Ionization from Multiple Orbitals in HCl

Akagi

Otobe

Staudte

et al. 2009

Science

Self Cite

296

251

View full text Add to dashboard Cite

A Lower Tunnel Among the peculiarities inherent in quantum mechanics is the ability of particles to tunnel through barriers that they lack the energy to surmount classically, as happens during radioactive decay. Strong laser fields can liberate electrons in this way from atoms and molecules. Akagi et al. (p. 1364 ) elegantly confirm that tunneling is not limited to the highest-energy electrons in a system by mapping the energy and momentum of both the ejected electron and positive ion produced when an intense laser pulse impinges on hydrogen chloride. When the molecule adopts specific orientations relative to the laser field, tunneling occurs from lower-lying states, as well as the highest-energy occupied orbital. This raises the possibility of tunneling microscopy capable of imaging the electronic structure of single molecules.

show abstract

mentioning

confidence: 88%

“…This process is the analog to the creation of vibrational wave packets in molecules by tunneling (28,29). Whereas vibrational wave packets typically evolve on the femtosecond scale, bound electron wave packets exhibit true attosecond dynamics and are expected to be a ubiquitous feature of laser-driven tunneling in both molecular gases and solids (14).…”

mentioning

confidence: 99%

Laser Tunnel Ionization from Multiple Orbitals in HCl

Akagi

Otobe

Staudte

et al. 2009

Science

Self Cite

296

251

View full text Add to dashboard Cite

show abstract

“…We attribute the anomalous anisotropy of HHG to a nonperturbative, highly directional, field-induced nonlinear current. One potential contribution would be from the possible dependence of tunnelling rate on crystallographic directions if the reduced electron and hole mass were different in different directions 21 . In MgO, the effective mass of electron and hole are isotropic around the minimum bandgap at the point 22 .…”

mentioning

confidence: 99%

Anisotropic high-harmonic generation in bulk crystals

2016

View full text Add to dashboard Cite

The microscopic valence electron density determines the optical, electronic, structural and thermal properties of materials. However, current techniques for measuring this electron charge density are limited: for example, scanning tunnelling microscopy is confined to investigations at the surface, and electron di raction requires very thin samples to avoid multiple scattering 1 . Therefore, an optical method is desirable for measuring the valence charge density of bulk materials. Since the discovery of high-harmonic generation (HHG) in solids 2 , there has been growing interest in using HHG to probe the electronic structure of solids 3-11 . Here, using single-crystal MgO, we demonstrate that high-harmonic generation in solids is sensitive to interatomic bonding. We find that harmonic e ciency is enhanced (diminished) for semi-classical electron trajectories that connect (avoid) neighbouring atomic sites in the crystal. These results indicate the possibility of using materials' own electrons for retrieving the interatomic potential and thus the valence electron density, and perhaps even wavefunctions, in an all-optical setting.High-harmonic generation (HHG) in bulk crystal is attributed to the sub-cycle electronic motion driven by an intense laser field [2][3][4][5][6][7][8][9][10][11] . There has been a growing interest in utilizing HHG to probe the electronic structure of solids 8,9,11 . Vampa et al. reconstructed the momentum-dependent bandgap of ZnO along the -M direction using HHG from a two-colour driving field 11 . Luu et al. retrieved the energy dispersion of the lowest conduction band of SiO 2 assuming that the harmonics are produced by the intraband currents 8 . The dependence of solid-state HHG on the coupling of multiple electronic bands has also been identified with the production of even harmonics in GaSe 9 and the emergence of a second plateau in rare-gas solids 12 . These findings show the possibility of using solidstate HHG to probe the electronic band structures in solids, but the analyses are so far limited to one dimension. For a complete electronic structure, it is desirable to exploit the microscopic process to measure the periodic potential in three dimensions (real space). This is analogous to tomographic imaging of a molecule, where the three-dimensional spatial information (that is, orbital wavefunction) of the target molecule is extracted [13][14][15] . Those measurement techniques are based critically on the dependence of HHG efficiency on molecular alignment with respect to the laser field 16 .In this letter, we demonstrate the strong sensitivity of HHG to the atomic-scale structure in the cubic wide-bandgap crystal MgO. First, using a linearly polarized field, we measure a highly anisotropic angular distribution in high-harmonic signal-despite the isotropic linear and weakly anisotropic nonlinear optical properties of the cubic crystal in the perturbative regime 17 . Second, we observe a strong ellipticity dependence of the HHG yield similar to the gas-phase HHG 18 for small elliptic...

show abstract

“…For example, multiphoton ionization of crystalline dielectrics was found to depend on sample orientation due to direction dependence of the effective mass of the electron [1]. Intense ultrashort laser pulses rapidly produce high carrier densities forming a plasma that can subsequently interact with incident light leading to polarization-dependent absorption.…”

Section: Introductionmentioning

confidence: 99%