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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
Contrôle cohérent
NO2
AOPDF
Caractérisation complète
Femtosecond lasers
ELEMENTAL FRACTIONATION
Femtosecond pulses
Wave packet interferences
Velocity map imaging
Molecular dynamics
ClN3
7960Jv
4230Kq
Echantillon multidiffusant
Acétylène
Chlorine azide
Femtosecond pulse
4225Ja
Quantum dots
Azoture de chlore
Diffractive optical element
Factorization
Coherent pulse propagation
7867Pt
Cold field emission
Pump-probe
Attosecond
Femtoseconde
Caractérisation
Cold molecules
Optical Parametric Amplifier
Ultrashort lasers
Number theory
Mise en forme d'impulsions
Quantum state measurement
Ultraviolet
4265Ky
Ultrashort pulses
CHARGE-TRANSFER
Characterisation
Femtosecond spectroscopy
Photoemission
CIN3
Spin-orbit precession
Boîte quantique semiconductrice
C2H2
CYCLIC-N-3
Chirped laser pulses
Bell's inequality
CHLORINE AZIDE
Chirp modulation rotational states quantum theory energy level crossing laser beams dissociation
Interférences de chemins quantiques
ENERGY
Transitoires cohérents
Femtosecond
Coherent control
Génération d'harmoniques d'ordre élevé
Couplage spatio-temporel
Mise en forme d'impulsion
Extreme ultraviolet
Factorisation
Impulsions à dérive de fréquence
Anharmonicity
Champ fort
Diamond nanotip
Half revival
Chirped pulses
Coherent Transient
Passage adiabatique rapide
Atom-photon collisions
ATOMS
Oscillations de Rabi
Caractérisation spatio-temporelle
Coherent Transients
Time-resolved photoelectron spectroscopy
Rabi oscillations
Attoseconde
Excited states sodium
Autocorrelation function
Femtosecond laser
Emission par champ froid
Rubidium atom
4265Re
Contrôle spatio-temporel
ALIGNED MOLECULES
XUV
Azulene
Pulse shaping
Dynamique moléculaire
Quantum path interferences
Expériences pompe-sonde
Photoémission
Ultrafast nonlinear optics
Cold Molecules
Expérience pompe-sonde
Femtochemistry
Gauss sums
Adiabatic rapid passage
Complete characterization
Coherent transients