High harmonic generation tomography of impurities in solids: Conceptual analysis

Almalki, S.; Parks, Andrew M.; Bart, Graeme; Corkum, P. B.; Brabec, Thomas; McDonald, Chris

doi:10.1103/physrevb.98.144307

Cited by 41 publications

(26 citation statements)

References 50 publications

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“…Therefore we attribute the enhancement of HHG in the donordoped system to the highest occupied impurity orbital that has an isolated energy within the BG. We note that impurity-state HHG was modeled in a recent work [50] taking only the impurity-state contribution into account FIG . 5.…”

Section: Role Of a Single Impurity Orbitalmentioning

confidence: 99%

Enhanced high-order harmonic generation in donor-doped band-gap materials

Hansen

Madsen

2019

Phys. Rev. A

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We find that a donor-doped band-gap material can enhance the overall high-order harmonic generation (HHG) efficiency by several orders of magnitude, compared with undoped and acceptordoped materials. This significant enhancement, predicted by time-dependent density functional theory simulations, originates from the highest occupied impurity state which has an isolated energy located within the band gap. The impurity-state HHG is rationalized by a three-step model, taking into account that the impurity-state electron tunnels into the conduction band and then moves according to its band structure until recombination. In addition to the improvement of the HHG efficiency, the donor-type doping results in a harmonic cutoff different from that in the undoped and acceptor-doped cases, explained by semiclassical analysis for the impurity-state HHG.

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Section: Role Of a Single Impurity Orbitalmentioning

confidence: 99%

Enhanced high-order harmonic generation in donor-doped band-gap materials

Hansen

Madsen

2019

Phys. Rev. A

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“…41 The conceptual idea for the tomographic imaging of shallow impurities in solids, within a one-dimensional hydrogenic model, has been developed by Corkum and co-workers. 42 Even though these pioneering works have shown that defects can influence HHG, many points remain elusive. So far, only model systems in one dimension have been considered, and no investigation of realistic defects (through geometry optimisation and relaxation of atomic forces) has been carried out.…”

Section: Introductionmentioning

confidence: 99%

High-harmonic generation from spin-polarised defects in solids

et al. 2020

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The generation of high-order harmonics in gases enabled to probe the attosecond electron dynamics in atoms and molecules with unprecedented resolution. Extending these techniques to solids, which were originally developed for atomic and molecular gases, requires a fundamental understanding of the physics that has been partially addressed theoretically. Here, we employ timedependent density-functional theory to investigate how the electron dynamics resulting in high-harmonic emission in monolayer hexagonal boron nitride is affected by the presence of vacancies. We show how these realistic spin-polarised defects modify the harmonic emission and demonstrate that important differences exist between harmonics from a pristine solid and a defected solid. In particular, we found that the different spin channels are affected differently by the presence of the spin-polarised point defect. Moreover, the localisation of the wavefunction, the geometry of the defect, and the electron-electron interaction are all crucial ingredients to describe high-harmonic generation in defected solids.npj Computational Materials (2020) 6:10 ; https://doi.

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“…In most of the theoretical studies so far, the solid-state system interacting with the laser field is treated as a perfect crystal with a periodic lattice structure. Theoretical models for HHG in a solid with some form of disorder have only been considered very recently, e.g., for investigating effects of doping-type impurities [14,15] and for simulating a two-band tight-binding model of Anderson disorder [16]. Recent experiments have demonstrated HHG in amorphous solids [17,18] and liquids [19], implying that a perfect periodic lattice is not a stringent requirement for HHG in condensed-matter systems.…”

Section: Introductionmentioning

confidence: 99%

High-order harmonic generation in imperfect crystals

Hansen

Madsen

2019

Phys. Rev. A

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High-order harmonic generation (HHG) in imperfect crystals, where the disorder is modeled by random shifts of the ionic positions, is studied using time-dependent density-functional theory. When irradiated by midinfrared laser pulses, the disorder-free system produces HHG spectra with two plateaus. Compared with the disorder-free system, disordered systems are found to emit suppressed harmonics in the first plateau region and enhanced harmonics in the second plateau region. The suppression of harmonics in the first plateau becomes less pronounced when decreasing the displacement of the nuclei, while the enhancement in the second plateau region is insensitive to the range of the ionic displacement. We have confirmed these findings for many different disordered sample systems and for different laser field strengths. The increase of the HHG signals in the second plateau region is proposed to stem from a change of the dynamics in the system, evidenced by the transition matrix elements between the field-free Kohn-Sham orbitals. In addition, a time-frequency profile of HHG spectra shows that the emission of harmonics is less regular in the time domain for a disordered system than for the disorder-free system.

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High harmonic generation tomography of impurities in solids: Conceptual analysis

Cited by 41 publications

References 50 publications

Enhanced high-order harmonic generation in donor-doped band-gap materials

Enhanced high-order harmonic generation in donor-doped band-gap materials

High-harmonic generation from spin-polarised defects in solids

High-order harmonic generation in imperfect crystals

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