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We study optical field emission from silver nanotips, showing the combined influence of the illumination wavelength and the exact shape of the nanotip on the strong-field response. This is particularly relevant in the case of FIB milled nano tips, where the nanotip fabrication capabilities could become a new ingredient for the study of strong-field physics. The influence of the thermal load on the nanotip and its effect on the emission is studied as well by switching the repetition rate of the laser source from 1 kHz to 62 MHz, showing a clear transition towards the quenching of the strongfield emission.
Bell's inequality violation experiments are becoming increasingly popular in the practical teaching of undergraduate and master's degree students. Bell's parameter S is obtained from 16 polarization correlation measurements performed on entangled photons pairs. We first report here a detailed analysis of the uncertainty u(S) of Bell's parameter taking into account coincidence count statistics and errors in polarizers' orientation. We show using both computational modeling and experimental measurement that the actual sequence of the polarizer settings has an unexpected and strong influence on the error budget. This result may also be relevant to measurements in other settings in which errors in parameters may have non-random effects in the measurement.
We report results of experimental investigation of field electron emission from diamond nanoemitters. The measurements were performed with single crystal diamond needles fixed at tungsten tips. The voltage drop along diamond needles during emission was revealed and measured using electron energy spectroscopy. The observed linear dependence of the voltage drop in diamond on voltage applied to the tungsten tip is explained in the frame of a simple macroscopic electrical model combining Poole–Frenkel conduction along the diamond tip and Fowler–Nordheim tunneling at the diamond-vacuum junction. Experimental evidences of electron emission sensitivity to laser illumination are discussed for possible modification of diamond emitter characteristics and voltage drop.
High-order harmonic generation in polyatomic molecules generally involves multiple channels of ionization. Their relative contribution can be strongly influenced by the presence of resonances, whose assignment remains a major challenge for high-harmonic spectroscopy. Here we present a multi-modal approach for the investigation of unaligned polyatomic molecules, using SF6 as an example. We combine methods from extreme-ultraviolet spectroscopy, above-threshold ionization and attosecond metrology. Fragment-resolved above-threshold ionization measurements reveal that strong-field ionization opens at least three channels. A shape resonance in one of them is found to dominate the signal in the 20–26 eV range. This resonance induces a phase jump in the harmonic emission, a switch in the polarization state and different dynamical responses to molecular vibrations. This study demonstrates a method for extending high-harmonic spectroscopy to polyatomic molecules, where complex attosecond dynamics are expected.
Sujets
Femtosecond pulse
Cold field emission
Emission par champ froid
Oscillations de Rabi
Photoémission
Ultraviolet
4230Kq
Azoture de chlore
Number theory
C2H2
Couplage spatio-temporel
AOPDF
Chlorine azide
Pump-probe
ClN3
Interférences de chemins quantiques
CYCLIC-N-3
Quantum path interferences
CIN3
Factorization
Complete characterization
Extreme ultraviolet
Rubidium atom
ATOMS
Gauss sums
XUV
Ultrafast nonlinear optics
Coherent Transient
Spin-orbit precession
Diffractive optical element
Ultrashort pulses
Photoemission
Contrôle cohérent
Adiabatic rapid passage
Expériences pompe-sonde
Chirped pulses
Contrôle spatio-temporel
4265Re
Coherent pulse propagation
Passage adiabatique rapide
Wave packet interferences
Characterisation
Coherent Transients
Excited states sodium
Femtosecond lasers
Echantillon multidiffusant
Optical Parametric Amplifier
CHARGE-TRANSFER
Dynamique moléculaire
Mise en forme d'impulsions
Molecular dynamics
7867Pt
Coherent control
Femtoseconde
Time-resolved photoelectron spectroscopy
Anharmonicity
Caractérisation
Quantum dots
Chirped laser pulses
Attoseconde
ENERGY
4265Ky
Pulse shaping
Impulsions à dérive de fréquence
ALIGNED MOLECULES
Femtosecond spectroscopy
CHLORINE AZIDE
4225Ja
Velocity map imaging
Caractérisation spatio-temporelle
Bell's inequality
Boîte quantique semiconductrice
Caractérisation complète
Ultrashort lasers
Femtosecond
Factorisation
Cold Molecules
Transitoires cohérents
Femtosecond pulses
Half revival
Attosecond
NO2
Atom-photon collisions
Chirp modulation rotational states quantum theory energy level crossing laser beams dissociation
Femtochemistry
Acétylène
Autocorrelation function
Mise en forme d'impulsion
7960Jv
Rabi oscillations
Azulene
Femtosecond laser
Champ fort
Génération d'harmoniques d'ordre élevé
Diamond nanotip
Quantum state measurement
Expérience pompe-sonde
Cold molecules
ELEMENTAL FRACTIONATION
Coherent transients
Statistiques
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