84 research outputs found
Dynamical characteristics of Rydberg electrons released by a weak electric field
The dynamics of ultra-slow electrons in the combined potential of an ionic
core and a static electric field is discussed. With state-of-the-art detection
it is possible to create such electrons through strong intense-field
photo-absorption and to detect them via high-resolution time-of-flight
spectroscopy despite their very low kinetic energy. The characteristic feature
of their momentum spectrum, which emerges at the same position for different
laser orientations, is derived and could be revealed experimentally with an
energy resolution of the order of 1meV.Comment: 5 pages, 5 figure
Multiorbital tunneling ionization of the CO molecule
We coincidently measure the molecular frame photoelectron angular
distribution and the ion sum-momentum distribution of single and double
ionization of CO molecules by using circularly and elliptically polarized
femtosecond laser pulses, respectively. The orientation dependent ionization
rates for various kinetic energy releases allow us to individually identify the
ionizations of multiple orbitals, ranging from the highest occupied to the next
two lower-lying molecular orbitals for various channels observed in our
experiments. Not only the emission of a single electron, but also the
sequential tunneling dynamics of two electrons from multiple orbitals are
traced step by step. Our results confirm that the shape of the ionizing
orbitals determine the strong laser field tunneling ionization in the CO
molecule, whereas the linear Stark effect plays a minor role.Comment: This paper has been accepted for publication by Physical Review
Letter
Ultrafast preparation and strong-field ionization of an atomic Bell-like state
Molecules are many body systems with a substantial amount of entanglement
between their electrons. Is there a way to break the molecular bond of a
diatomic molecule and obtain two atoms in their ground state which are still
entangled and form a Bell-like state? We present a scheme that allows for the
preparation of such entangled atomic states from single oxygen molecules on
femtosecond time scales. The two neutral oxygen atoms are entangled in the
magnetic quantum number of their valence electrons. In a time-delayed probe
step, we employ non-adiabatic tunnel ionization, which is a magnetic quantum
number-sensitive mechanism. We then investigate correlations by comparing
single and double ionization probabilities of the Bell-like state. The
experimental results agree with the predictions for an entangled state.Comment: 20 pages, 7 figures, 1 tabl
Angular dependence of the Wigner time delay upon strong field ionization from an aligned p-orbital
We present experimental data on the strong-field ionization of the argon
dimer in a co-rotating two-color (CoRTC) laser field. We observe a sub-cycle
interference pattern in the photoelectron momentum distribution and infer the
Wigner time delay using holographic angular streaking of electrons (HASE). We
find that the Wigner time delay varies by more than 400 attoseconds as a
function of the electron emission direction with respect to the molecular axis.
The measured time delay is found to be independent of the parity of the
dimer-cation and is in good agreement with our theoretical model based on the
ionization of an aligned atomic p-orbital.Comment: 6 pages, 4 figure
- …