Even harmonic generation in isotropic media of dissociating homonuclear molecules

  title={Even harmonic generation in isotropic media of dissociating homonuclear molecules},
  author={R. E. F. Silva and Paula Riviere and Felipe Morales and Olga Smirnova and Misha (Mikhail) Ivanov and Fernando Mart{\'i}n},
  journal={Scientific Reports},
Isotropic gases irradiated by long pulses of intense IR light can generate very high harmonics of the incident field. It is generally accepted that, due to the symmetry of the generating medium, be it an atomic or an isotropic molecular gas, only odd harmonics of the driving field can be produced. Here we show how the interplay of electronic and nuclear dynamics can lead to a marked breakdown of this standard picture: a substantial part of the harmonic spectrum can consist of even rather than… 
27 Citations
Odd-even harmonic generation from oriented CO molecules in linearly polarized laser fields and the influence of the dynamic core-electron polarization.
A detailed theoretical study of the odd-even harmonics generated from the polar molecule CO by the method based on numerically solving the time-dependent Schrödinger equation within the single-active-electron approximation, which shows that this symmetry is broken at orientation angles other than 90° resulting in the even-even harmonic generation and a non-trivial even-to-odd harmonics ratio strongly dependent on the molecular orientation.
Time-resolved high harmonic spectroscopy of dynamical symmetry breaking in bi-circular laser fields: the role of Rydberg states.
It is demonstrated that when the second harmonic either precedes or is more intense than the fundamental field, the weak effects of dynamical symmetry breaking caused by finite pulse duration are amplified by electrons trapped in Rydberg orbits (i.e., Freeman resonances), and that the forbidden harmonic lines are a witness of this.
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Intensity distributions and isolated attosecond pulse generation from the molecular high-order harmonic generation (MHHG) in H2+ and T2+ driven by the nonhomogeneous field have been theoretically
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The isotopic effects in the energy shift of the HHG spectra caused by the nuclear motion of the molecules are measured to pave an accessible route toward monitoring the ultrafast nuclear dynamics and even tracing a chemical reaction in real time.
Generation of even harmonics with a small redshift in an asymmetric nonhomogeneous laser field
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This work experimentally determined and theoretically evaluated vibrationally resolved photoionization cross sections of SF6 up to 80 eV photon energies, with an emphasis on the E2T1u channel, for which vibrational progressions are fully resolved in the experiment.
The shift of harmonics with different initial vibrational states in the H2+ molecular ion
Molecular high-order harmonic generation of H2+ and its isotopes is investigated by numerical simulations of the non-Born–Oppenheimer time-dependent Schrödinger equations. The general characteristic
Electron‐Nuclear Dynamics in Molecular Harmonic Generation Driven by a Plasmonic Nonhomogeneous Field
Electron (z)‐nuclear (R) dynamics in the molecular high‐order harmonic generation (MHHG) from H2+ driven by the plasmonic nonhomogeneous field, generated by the surface plasmon polaritons in the


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Interaction of a laser pulse with a centrally symmetric medium, such as an isotropic gas of atoms, leads to the generation of harmonic emission which contains exclusively odd harmonics of the
Theory of high-harmonic generation by low-frequency laser fields.
A simple, analytic, and fully quantum theory of high-harmonic generation by low-frequency laser fields is presented and the exact quantum-mechanical formula for the harmonic cutoff that differs from the phenomenological law Ip+3.17Up is presented.
High harmonic interferometry of multi-electron dynamics in molecules
These findings establish high harmonic interferometry as an effective approach to resolving multi-electron dynamics with sub-Ångström spatial resolution arising from the de Broglie wavelength of the recombining electron, and attosecond temporal resolution arisen from the timescale ofThe recombination event.
Anatomy of strong field ionization II: to dress or not to dress?
We analyse S-matrix-type approaches to strong-field ionization by an intense few-cycle laser pulse. We derive simple modifications of approximate S-matrix-type approaches that either neglect the
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Redshifts as frequency modulation (FM) of intercycle dynamics in MHOHG is demonstrated, induced by nuclear motion using intense laser pulses, which can be used to retrieve the nuclear dynamics.
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Using the example of the H 2 + ?> molecular ion and its isotopes, we show how the Coulomb explosion triggered by ionization of the molecule can be used to reconstruct the emission times and identify
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We investigate the control of the vibrational dynamics in the hydrogen molecular ion H+2 using strong femto-second infrared control-laser pulses. For our three-dimensional calculations, we use
Charge-resonance-enhanced ionization of diatomic molecular ions by intense lasers.
  • Zuo, Bandrauk
  • Physics, Chemistry
    Physical review. A, Atomic, molecular, and optical physics
  • 1995
The ionization rate of the H{sub 2}{sup +} molecular ion in intense, short-pulse laser fields is found to exhibit maxima at large {ital R}, exceeding the atom limit by an order of magnitude.
Signatures of nuclear motion in molecular high-order harmonics and in the generation of attosecond pulse trains by ultrashort intense laser pulses
Non-Born–Oppenheimer time-dependent Shrödinger equation numerical simulations of the nonlinear nonperturbative response of 1D H2, H+2 molecules (and their isotopes) in few cycle intense 800 nm laser
Ultraviolet surprise: Efficient soft x-ray high-harmonic generation in multiply ionized plasmas
Surprisingly, the high ultraviolet refractive indices of both neutral atoms and ions enabled effective phase matching, even in a multiply ionized plasma, which could presage a more generally efficient means of creating x-ray pulses for fundamental dynamics studies as well as technological applications.