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Thomas Brabec - One of the best experts on this subject based on the ideXlab platform.
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Wannier quasi-classical approach to High Harmonic Generation in semiconductors
arXiv: Mesoscale and Nanoscale Physics, 2020Co-Authors: Andrew M. Parks, Paul B. Corkum, C. R. Mcdonald, Marco Taucer, Guilmot Ernotte, Adam Thorpe, Thomas BrabecAbstract:We develop a quasi-classical theory of High Harmonic Generation in semiconductors based on an interband current that has been transformed from Bloch to Wannier basis. The Wannier quasi-classical approach reveals a complete picture of the mechanisms shaping High Harmonic Generation, such that quantitative agreement with full quantum calculations is obtained. The intuitive picture revealed by quasi-classical wavepacket propagation will be helpful in the interpretation and design of High Harmonic and attosecond experiments. Beyond that, the capacity to quantitatively model quantum dynamics with classical trajectories should prove useful for a wider spectrum of condensed matter research, including coherent control, transport theory, and strong field physics.
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High Harmonic Generation tomography of impurities in solids: conceptual analysis
Physical Review B, 2018Co-Authors: S. Almalki, Paul B. Corkum, Thomas Brabec, A. M. Parks, G. Bart, C. R. McdonaldAbstract:A three step model for High Harmonic Generation from impurities in solids is developed. The process is found to be similar to High Harmonic Generation in atomic and molecular gases with the main difference coming from the non-parabolic nature of the bands. This opens a new avenue for strong field atomic and molecular physics in the condensed matter phase. As a first application, our conceptual study demonstrates the feasibility of tomographic measurement of impurity orbitals.
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Interband Bloch oscillation mechanism for High-Harmonic Generation in semiconductor crystals
Physical Review A, 2015Co-Authors: C. R. Mcdonald, Paul B. Corkum, Giulio Vampa, Thomas BrabecAbstract:High Harmonic Generation in semiconductors is analyzed for High mid-infrared laser intensities for which the electron-hole pair is driven beyond the first Brillouin zone and exhibits Bloch oscillations. We find that even a two-band analysis exhibits second and Higher plateaus. Whereas the first plateau is shown to be consistent with High Harmonic Generation through electron-hole recollision, the Higher plateaus arise from dynamic Bloch oscillations; however, the driving process is interband in nature, in contrast to the generally accepted intraband Bloch oscillation mechanism. Energy conservation is fulfilled, as Harmonics beyond the first plateau come from a cascaded nonlinearity.
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Theory of High-Harmonic Generation in solids
Journal of Physics: Conference Series, 2015Co-Authors: C. R. Mcdonald, Paul B. Corkum, Giulio Vampa, G. Orlando, Thomas BrabecAbstract:High-Harmonic Generation (HHG) in bulk crystals exposed to intense mid-infrared lasers with photon energies below the bandgap is investigated theoretically. A three dimensional, two-band model that considers both interband and intraband currents is used. It is shown that the interband current is the dominant mechanism for HHG in solids. A physical interpretation of interband HHG – similar to atomic HHG – is provided by saddle point analysis. The effects of dephasing time and driving field wavelength on the Harmonic specrum are investigated.
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High-Harmonic Generation in Solids: Bridging the Gap Between Attosecond Science and Condensed Matter Physics
IEEE Journal of Selected Topics in Quantum Electronics, 2015Co-Authors: Giulio Vampa, C. R. Mcdonald, Alec Fraser, Thomas BrabecAbstract:We review recent progress in understanding the dominant mechanism driving High-Harmonic Generation in solids. Three-dimensional two-band single active electron calculations predict that the major emission arises from the recombination of electron-hole pairs upon their creation and acceleration in the laser field, in analogy to atomic High-Harmonic Generation. The main goal of this study is to review a simple quasi-classical trajectory formalism and use it to better understand the fundamental properties of High-Harmonic Generation in solids and how they compare to High-Harmonic Generation in atomic and molecular gases. The simple formalism presents a valuable tool for extending attosecond science from the gas to the condensed matter phase. This is demonstrated by discussing the potential synthesis of attosecond pulses from solids.
C. R. Mcdonald - One of the best experts on this subject based on the ideXlab platform.
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Wannier quasi-classical approach to High Harmonic Generation in semiconductors
arXiv: Mesoscale and Nanoscale Physics, 2020Co-Authors: Andrew M. Parks, Paul B. Corkum, C. R. Mcdonald, Marco Taucer, Guilmot Ernotte, Adam Thorpe, Thomas BrabecAbstract:We develop a quasi-classical theory of High Harmonic Generation in semiconductors based on an interband current that has been transformed from Bloch to Wannier basis. The Wannier quasi-classical approach reveals a complete picture of the mechanisms shaping High Harmonic Generation, such that quantitative agreement with full quantum calculations is obtained. The intuitive picture revealed by quasi-classical wavepacket propagation will be helpful in the interpretation and design of High Harmonic and attosecond experiments. Beyond that, the capacity to quantitatively model quantum dynamics with classical trajectories should prove useful for a wider spectrum of condensed matter research, including coherent control, transport theory, and strong field physics.
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Attosecond spectral singularities in solid-state High-Harmonic Generation
Nature Photonics, 2020Co-Authors: Ayelet Julie Uzan, Barry D. Bruner, Gal Orenstein, Álvaro Jiménez-galán, C. R. Mcdonald, R. E. F. Silva, Nikolai D. Klimkin, Valérie Blanchet, Talya Arusi-parpar, Michael KrugerAbstract:Strong-field-driven electric currents in condensed-matter systems are opening new frontiers in petahertz electronics. In this regime, new challenges are arising as the roles of band structure and coherent electron–hole dynamics have yet to be resolved. Here, by using High-Harmonic Generation spectroscopy, we reveal the underlying attosecond dynamics that dictates the temporal evolution of carriers in multi-band solid-state systems. We demonstrate that when the electron–hole relative velocity approaches zero, enhanced constructive interference leads to the appearance of spectral caustics in the High-Harmonic Generation spectrum. We introduce the role of the dynamical joint density of states and identify its mapping into the spectrum, which exhibits singularities at the spectral caustics. By studying these singularities, we probe the structure of multiple unpopulated High conduction bands. High-Harmonic waves are generated from a MgO crystal under experimental conditions where the simple semi-classical analysis fails. High-Harmonic Generation spectroscopy directly probes the strong-field attosecond dynamics over multiple bands.
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High Harmonic Generation tomography of impurities in solids: conceptual analysis
Physical Review B, 2018Co-Authors: S. Almalki, Paul B. Corkum, Thomas Brabec, A. M. Parks, G. Bart, C. R. McdonaldAbstract:A three step model for High Harmonic Generation from impurities in solids is developed. The process is found to be similar to High Harmonic Generation in atomic and molecular gases with the main difference coming from the non-parabolic nature of the bands. This opens a new avenue for strong field atomic and molecular physics in the condensed matter phase. As a first application, our conceptual study demonstrates the feasibility of tomographic measurement of impurity orbitals.
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Interband Bloch oscillation mechanism for High-Harmonic Generation in semiconductor crystals
Physical Review A, 2015Co-Authors: C. R. Mcdonald, Paul B. Corkum, Giulio Vampa, Thomas BrabecAbstract:High Harmonic Generation in semiconductors is analyzed for High mid-infrared laser intensities for which the electron-hole pair is driven beyond the first Brillouin zone and exhibits Bloch oscillations. We find that even a two-band analysis exhibits second and Higher plateaus. Whereas the first plateau is shown to be consistent with High Harmonic Generation through electron-hole recollision, the Higher plateaus arise from dynamic Bloch oscillations; however, the driving process is interband in nature, in contrast to the generally accepted intraband Bloch oscillation mechanism. Energy conservation is fulfilled, as Harmonics beyond the first plateau come from a cascaded nonlinearity.
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Theory of High-Harmonic Generation in solids
Journal of Physics: Conference Series, 2015Co-Authors: C. R. Mcdonald, Paul B. Corkum, Giulio Vampa, G. Orlando, Thomas BrabecAbstract:High-Harmonic Generation (HHG) in bulk crystals exposed to intense mid-infrared lasers with photon energies below the bandgap is investigated theoretically. A three dimensional, two-band model that considers both interband and intraband currents is used. It is shown that the interband current is the dominant mechanism for HHG in solids. A physical interpretation of interband HHG – similar to atomic HHG – is provided by saddle point analysis. The effects of dephasing time and driving field wavelength on the Harmonic specrum are investigated.
Paul B. Corkum - One of the best experts on this subject based on the ideXlab platform.
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High-Harmonic Generation in metallic titanium nitride.
arXiv: Optics, 2020Co-Authors: A. Korobenko, David M. Villeneuve, Soham Saha, Alan T. K. Godfrey, M. Gertsvolf, Andrei Yu. Naumov, Alexandra Boltasseva, Vladimir M. Shalaev, Paul B. CorkumAbstract:High-Harmonic Generation is the cornerstone of nonlinear optics. It has been demonstrated in a wide range of crystalline systems including dielectrics, semiconductors, and semi-metals, as well as in gases, leaving metals out due to their low damage threshold. Here, we report on the High-Harmonic Generation in metallic titanium nitride (TiN) films. TiN is a refractory plasmonic metal, known for its High melting temperature and laser damage threshold, with optical properties similar to those of gold. We show that TiN can withstand laser pulses with peak intensities as High as 13 TW/cm$^2$, one order of magnitude Higher than gold, enabling the emission of intraband Harmonics up to photon energies of 11 eV. These Harmonics can pave the way for compact and efficient plasmonic devices producing vacuum ultraviolet (VUV) frequency combs. Through numerical calculations and experimental studies, we show that the intensity scaling and angular anisotropy of the emitted VUV radiation stem from the anisotropic conduction band structure of TiN, thus confirming its intraband origin.
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Wannier quasi-classical approach to High Harmonic Generation in semiconductors
arXiv: Mesoscale and Nanoscale Physics, 2020Co-Authors: Andrew M. Parks, Paul B. Corkum, C. R. Mcdonald, Marco Taucer, Guilmot Ernotte, Adam Thorpe, Thomas BrabecAbstract:We develop a quasi-classical theory of High Harmonic Generation in semiconductors based on an interband current that has been transformed from Bloch to Wannier basis. The Wannier quasi-classical approach reveals a complete picture of the mechanisms shaping High Harmonic Generation, such that quantitative agreement with full quantum calculations is obtained. The intuitive picture revealed by quasi-classical wavepacket propagation will be helpful in the interpretation and design of High Harmonic and attosecond experiments. Beyond that, the capacity to quantitatively model quantum dynamics with classical trajectories should prove useful for a wider spectrum of condensed matter research, including coherent control, transport theory, and strong field physics.
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A Wannier Perspective On High Harmonic Generation In Solids
Frontiers in Optics + Laser Science APS DLS, 2019Co-Authors: Guilmot Ernotte, Marco Taucer, Paul B. CorkumAbstract:We theoretically investigate High-Harmonic Generation in a 1D crystal in the natural real-space basis for periodic systems, the Wannier states. A full quantum simulation confirms our semi-classical model and its interpretation.
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High Harmonic Generation tomography of impurities in solids: conceptual analysis
Physical Review B, 2018Co-Authors: S. Almalki, Paul B. Corkum, Thomas Brabec, A. M. Parks, G. Bart, C. R. McdonaldAbstract:A three step model for High Harmonic Generation from impurities in solids is developed. The process is found to be similar to High Harmonic Generation in atomic and molecular gases with the main difference coming from the non-parabolic nature of the bands. This opens a new avenue for strong field atomic and molecular physics in the condensed matter phase. As a first application, our conceptual study demonstrates the feasibility of tomographic measurement of impurity orbitals.
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Localized High Harmonic Generation in Semiconductor Nanostructures
Frontiers in Optics 2016, 2016Co-Authors: Murat Sivis, David M. Villeneuve, Marco Taucer, Kyle Johnston, Giulio Vampa, André Staudte, Andrei Naumov, Claus Ropers, Paul B. CorkumAbstract:Here, we investigate the enhancement and localization of High Harmonic Generation in a nanostructured ZnO-crystal by spectral analysis and microscopic imaging. We show a robust method of distinguishing site-selective Harmonic emission from the bulk emission.
Oren Cohen - One of the best experts on this subject based on the ideXlab platform.
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The quantum-optical nature of High Harmonic Generation.
Nature communications, 2020Co-Authors: Alexey Gorlach, Oren Cohen, Ofer Neufeld, Nicholas Rivera, Ido KaminerAbstract:High Harmonic Generation (HHG) is an extremely nonlinear effect generating coherent broadband radiation and pulse durations reaching attosecond timescales. Conventional models of HHG that treat the driving and emitted fields classically are usually very successful but inherently cannot capture the quantum-optical nature of the process. Although prior work considered quantum HHG, it remains unknown in what conditions the spectral and statistical properties of the radiation depart considerably from the known phenomenology of HHG. The discovery of such conditions could lead to novel sources of attosecond light having squeezing and entanglement. Here, we present a fully-quantum theory of extreme nonlinear optics, predicting quantum effects that alter both the spectrum and photon statistics of HHG, thus departing from all previous approaches. We predict the emission of shifted frequency combs and identify spectral features arising from the breakdown of the dipole approximation for the emission. Our results show that each frequency component of HHG can be bunched and squeezed and that each emitted photon is a superposition of all frequencies in the spectrum, i.e., each photon is a comb. Our general approach is applicable to a wide range of nonlinear optical processes, paving the way towards novel quantum phenomena in extreme nonlinear optics. Conventional models of High Harmonic Generation typically do not provide a full quantum description of all phenomena. Here, the authors develop a fully quantum theory for High Harmonic Generation and use it to study the emission from a quantum system in a strong field.
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Probing ultrafast electron correlations in High Harmonic Generation
Physical Review Research, 2020Co-Authors: Ofer Neufeld, Oren CohenAbstract:This paper develops an optical method to probe ultrafast electron correlations, based on bielliptical High Harmonic Generation. The authors use ab-initio numerical results to show that, with this approach, correlations are imprinted on the Harmonic emission spectra, appear in a wide energy range, and persist far from any material resonant behavior.
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On the Quantum-Optical Nature of High Harmonic Generation
Conference on Lasers and Electro-Optics, 2020Co-Authors: Alexey Gorlach, Oren Cohen, Ofer Neufeld, Nicholas Rivera, Ido KaminerAbstract:We show novel effects in High Harmonic Generation arising from the quantum nature of light. These effects include multiple shifted combs of High Harmonics, where each photon carries all the spectral information of the combs.
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High Harmonic Generation from multiply ionized argon extending beyond 500 eV
Conference on Lasers and Electro-Optics International Quantum Electronics Conference, 2009Co-Authors: Paul Arpin, Henry C. Kapteyn, Oren Cohen, Nicholas L. Wagner, Amy L. Lytle, Tenio Popmintchev, Margaret M. MurnaneAbstract:By combining pulse self-compression and High Harmonic Generation within a single waveguide, we demonstrate Harmonic emission from a multiply ionized gas, extending the cutoff photon energy in Ar to ≫ 500 eV.
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Quasi-periodic and random quasi-phase matching of High Harmonic Generation
Optics Letters, 2008Co-Authors: Alon Bahabad, Margaret M. Murnane, Oren Cohen, Henry C. KapteynAbstract:Quasi-phase matching schemes employing quasi-periodic or random spatial modulations, previously applied to perturbative nonlinear optics, are demonstrated theoretically for the extreme nonlinear optical process of High Harmonic Generation. We show that quasi-periodic quasi-phase matching of High Harmonic Generation can be used for simultaneous enhancement of arbitrarily chosen spectral regions. We also demonstrate enhancement of a single extremely wide bandwidth using random quasi-phase matching.
Henry C. Kapteyn - One of the best experts on this subject based on the ideXlab platform.
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High Harmonic Generation from multiply ionized argon extending beyond 500 eV
Conference on Lasers and Electro-Optics International Quantum Electronics Conference, 2009Co-Authors: Paul Arpin, Henry C. Kapteyn, Oren Cohen, Nicholas L. Wagner, Amy L. Lytle, Tenio Popmintchev, Margaret M. MurnaneAbstract:By combining pulse self-compression and High Harmonic Generation within a single waveguide, we demonstrate Harmonic emission from a multiply ionized gas, extending the cutoff photon energy in Ar to ≫ 500 eV.
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Time-Resolved Dynamics in N2O4 Probed Using High Harmonic Generation
Science, 2008Co-Authors: Xibin Zhou, Robynne Lock, Serguei Patchkovskii, Albert Stolow, Henry C. Kapteyn, Margaret M. MurnaneAbstract:The attosecond time-scale electron-recollision process that underlies High Harmonic Generation has uncovered extremely rapid electronic dynamics in atoms and diatomics. We showed that High Harmonic Generation can reveal coupled electronic and nuclear dynamics in polyatomic molecules. By exciting large amplitude vibrations in dinitrogen tetraoxide, we showed that tunnel ionization accesses the ground state of the ion at the outer turning point of the vibration but populates the first excited state at the inner turning point. This state-switching mechanism is manifested as bursts of High Harmonic light that is emitted mostly at the outer turning point. Theoretical calculations attribute the large modulation to suppressed emission from the first excited state of the ion. More broadly, these results show that High Harmonic Generation and strong-field ionization in polyatomic molecules undergoing bonding or configurational changes involve the participation of multiple molecular orbitals.
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Quasi-periodic and random quasi-phase matching of High Harmonic Generation
Optics Letters, 2008Co-Authors: Alon Bahabad, Margaret M. Murnane, Oren Cohen, Henry C. KapteynAbstract:Quasi-phase matching schemes employing quasi-periodic or random spatial modulations, previously applied to perturbative nonlinear optics, are demonstrated theoretically for the extreme nonlinear optical process of High Harmonic Generation. We show that quasi-periodic quasi-phase matching of High Harmonic Generation can be used for simultaneous enhancement of arbitrarily chosen spectral regions. We also demonstrate enhancement of a single extremely wide bandwidth using random quasi-phase matching.
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Optically-Induced Quasi-Phase Matching in High-Harmonic Generation
Frontiers in Optics 2008 Laser Science XXIV Plasmonics and Metamaterials Optical Fabrication and Testing, 2008Co-Authors: Oren Cohen, Henry C. Kapteyn, Amy L. Lytle, Xiaoshi Zhang, Margaret M. MurnaneAbstract:Weak counter-propagating pulse trains or multiple quasi-cw waves can induce complex amplitude and phase modulated structures in the High-Harmonic field. These “photonic” structures can be used for quasi-phase-matching the High-Harmonic Generation process.
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Intra-molecular dynamics probed using High-Harmonic Generation
2007 Quantum Electronics and Laser Science Conference, 2007Co-Authors: Xibin Zhou, Henry C. Kapteyn, Robynne Hooper, Nicholas L. Wagner, Margaret M. MurnaneAbstract:High Harmonic Generation is used to probe vibrational and electronic dynamics in small molecules. We impulsively excite vibrations in CF3C1 and observe oscillations in the Harmonic emission. We electronically excite CF3I and observe changes in the yield.
