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