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