Lightwave-controlled electron dynamics in graphene

We demonstrate that currents induced in graphene by ultrashort laser pulses are sensitive to the exact shape of the electric-field waveform. By increasing the field strength, we found a transition of the light–matter interaction from the weak-field to the strong-field regime at around 2 V/nm, where intraband dynamics influence interband transitions. In this strong-field regime, the light-matter interaction can be described by the wavenumber trajectories of electrons in the reciprocal space. For linearly polarized light the electron dynamics are governed by repeated sub-optical-cycle Landau-Zener transitions between the valence- and conduction band, resulting in Landau-Zener-Stuckelberg interference, whereas for circular polarized light this interference is supressed.

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Theoretical framework for classification and prediction of ultrafast and strong-field phenomena in solids

EPJ Web of Conferences ◽

10.1051/epjconf/201920504013 ◽

2019 ◽

Vol 205 ◽

pp. 04013

Author(s):

Stanislav Yu. Kruchinin ◽

Ferenc Krausz ◽

Vladislav S. Yakovlev

Keyword(s):

Density Matrix ◽

Time Scales ◽

Strong Field ◽

Laser Pulses ◽

Theoretical Framework ◽

Ultrashort Laser Pulses ◽

Matrix Equations ◽

Electron Dynamics ◽

Characteristic Energy ◽

Ultrashort Laser

We study the characteristic energy and time scales describing the coherent electron dynamics and decoherence phenomena in solids interacting with ultrashort laser pulses. Our analysis resulted in the derivation system of dimensionless adiabaticity parameters and derivation of the non-Markovian density-matrix equations applicable on arbitrary short timescales.

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A minimal subwavelength focal spot for the energy flux

Computer Optics ◽

10.18287/2412-6179-co-908 ◽

2021 ◽

Vol 5 (45) ◽

pp. 685-691

Author(s):

S.S. Stafeev ◽

V.D. Zaicev

Keyword(s):

Energy Flux ◽

Topological Charge ◽

Focal Spot ◽

Polarized Light ◽

Spot Size ◽

Optical Vortices ◽

Matter Interaction ◽

Linearly Polarized ◽

Light Matter Interaction ◽

Tight Focus

It is shown theoretically and numerically that circularly and linearly polarized incident beams produce at the tight focus identical circularly symmetric distributions of an on-axis energy flux. It is also shown that the on-axis energy fluxes from radially and azimuthally polarized optical vortices with unit topological charge are equal to each other. An optical vortex with azimuthal polarization is found to generate the minimum focal spot measured for the intensity (all other parameters being equal). Slightly larger (by a fraction of a percent) is the spot size calculated for the energy flux for the circularly and linearly polarized light. The spot size in terms of intensity is of importance in light-matter interaction, whereas the spot size in terms of energy flux affects the resolution in optical microscopy.

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Terahertz quantum plasmonics at nanoscales and angstrom scales

Nanophotonics ◽

10.1515/nanoph-2019-0436 ◽

2020 ◽

Vol 9 (2) ◽

pp. 435-451 ◽

Cited By ~ 1

Author(s):

Taehee Kang ◽

Young-Mi Bahk ◽

Dai-Sik Kim

Keyword(s):

Electron Tunneling ◽

Strong Field ◽

Field Enhancement ◽

Dipole Antenna ◽

Strong Light ◽

Metallic Structures ◽

Terahertz Pulses ◽

Matter Interaction ◽

Light Matter Interaction ◽

Quantum Phenomena

AbstractThrough the manipulation of metallic structures, light–matter interaction can enter into the realm of quantum mechanics. For example, intense terahertz pulses illuminating a metallic nanotip can promote terahertz field–driven electron tunneling to generate enormous electron emission currents in a subpicosecond time scale. By decreasing the dimension of the metallic structures down to the nanoscale and angstrom scale, one can obtain a strong field enhancement of the incoming terahertz field to achieve atomic field strength of the order of V/nm, driving electrons in the metal into tunneling regime by overcoming the potential barrier. Therefore, designing and optimizing the metal structure for high field enhancement are an essential step for studying the quantum phenomena with terahertz light. In this review, we present several types of metallic structures that can enhance the coupling of incoming terahertz pulses with the metals, leading to a strong modification of the potential barriers by the terahertz electric fields. Extreme nonlinear responses are expected, providing opportunities for the terahertz light for the strong light–matter interaction. Starting from a brief review about the terahertz field enhancement on the metallic structures, a few examples including metallic tips, dipole antenna, and metal nanogaps are introduced for boosting the quantum phenomena. The emerging techniques to control the electron tunneling driven by the terahertz pulse have a direct impact on the ultrafast science and on the realization of next-generation quantum devices.

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Nonlinear Behavior of Circularly Polarized Laser Beams Propagating through Sodium Vapor

Zeitschrift für Naturforschung A ◽

10.1515/zna-1993-5-602 ◽

1993 ◽

Vol 48 (5-6) ◽

pp. 621-623

Author(s):

B. Röhricht ◽

P. Eschle ◽

S. Dangel ◽

R. Holzner

Keyword(s):

Laser Light ◽

Polarized Light ◽

Nonlinear Behavior ◽

Laser Beams ◽

Sodium Vapor ◽

Circularly Polarized Light ◽

Circularly Polarized ◽

Left Hand ◽

Matter Interaction ◽

Light Matter Interaction

Abstract A variety of surprising effects arise from the nonlinear light-matter interaction of circularly polarized laser light propagating through sodium vapor. We present experimental evidence for an asymmetry in the absorption of left hand and right hand circularly polarized light as well as for the creation of a collimated light beam of apposite polarization within the light-matter interaction region. Both effects are not yet explained by common theories.

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Line Pattern in Plasma Polymer Films with Embedded Gold and Silver Nanoparticles by Irradiation with Ultrashort Laser Pulses

MRS Proceedings ◽

10.1557/proc-818-m12.17.1 ◽

2004 ◽

Vol 818 ◽

Author(s):

Andreas Kiesow ◽

Sven Strohkark ◽

Katrin Löschner ◽

Andreas Heilmann ◽

Alexander Podlipensky ◽

...

Keyword(s):

Silver Nanoparticles ◽

Laser Pulses ◽

Ultrashort Laser Pulses ◽

Organic Films ◽

Line Pattern ◽

Gold And Silver Nanoparticles ◽

Optical Film ◽

Pattern Structures ◽

Thin Organic Films ◽

Linearly Polarized

AbstractA method to generate line pattern structures in thin organic films with embedded gold and silver nanoparticles is introduced. The films are irradiated with ultrashort, linearly polarized laser pulses. As we find out from electron microscopy (TEM, SEM), periodically arranged line-like structures are formed after the irradiation. We have used so far three different laser wavelengths (266 nm, 400 nm, 800 nm). The resulting structure periods in the range of 170 nm to 600 nm indicate a linear correlation of the period length of the line structures and the wavelength of the incident laser light. The direction of the particle lines corresponds to the linear polarization of the laser pulses. The anisotropic structure modification is mirrored in corresponding anisotropic optical film properties.

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