237 citations · 3k across the 111 of their papers we have counts for
59 papers · 1 filter
Strong-field photoionization by circularly polarized light
Jonathan Dubois, Camille Lévêque, Jérémie Caillat +3
We demonstrate that strong-field ionization of atoms driven by circularly polarized light becomes an adiabatic process when described in the frame rotating with the laser field. As…
Symmetry-induced decoherence-free subspaces
Jonathan Dubois, Ulf Saalmann, Jan Michael Rost
Preservation of coherence is a fundamental yet subtle phenomenon in open systems. We uncover its relation to symmetries respected by the system Hamiltonian and its coupling to the…
Enhanced high-order harmonics through periodicity breaks: from backscattering to impurity states
Chuan Yu, Ulf Saalmann, Jan M. Rost
Backscattering of delocalized electrons has been recently established [Phys. Rev. A 105, L041101 (2022)] as a mechanism to enhance high-order harmonic generation (HHG) in periodic…
Probing ultracold gases using photoionization fine structure
P. Giannakeas, Matthew T. Eiles, L. Alonso +2
Photoionization of atoms immersed in an environment such as an ultracold gas is investigated. We show that the interference of two ionization pathways, one passing directly to the…
Anderson localization of a Rydberg electron
Matthew T. Eiles, Alexander Eisfeld, Jan M. Rost
Highly excited Rydberg atoms inherit their level structure, symmetries, and scaling behavior from the hydrogen atom. We demonstrate that these fundamental properties enable a therm…
Non-adiabatic dynamics in Rydberg gases with random atom positions
Ritesh Pant, Rajat Agrawal, Sebastian Wüster +1
Assemblies of highly excited Rydberg atoms in an ultracold gas can be set into motion by a combination of van-der-Waals and resonant dipole-dipole interactions. Thereby, the collec…
Non-adiabatic ionization with tailored laser pulses
Sajad Azizi, Ulf Saalmann, Jan M Rost
Non-adiabatic photo-ionization is difficult to control as it relies on the derivatives of the envelope and not on phase-details of the short ionizing pulse. Here, we introduce a ca…
High harmonics from backscattering of delocalized electrons
Chuan Yu, Ulf Saalmann, Jan M. Rost
It is shown that electron backscattering can enhance high-harmonic generation in periodic systems with broken translational symmetry. Paradigmatically, we derive for a finite chain…
Semiclassical Lindblad master equation for spin dynamics
J. Dubois, Ulf Saalmann, Jan M. Rost
We derive the semi-classical Lindblad master equation in phase space for both canonical and non-canonical Poisson brackets using the Wigner-Moyal formalism and the Moyal star-produ…
Perspectives for analyzing non-linear photo ionization spectra with deep neural networks trained with synthetic Hamilton matrices
Sajal Kumar Giri, Lazaro Alonso, Ulf Saalmann +1
We have constructed deep neural networks, which can map fluctuating photo-electron spectra obtained from noisy pulses to spectra from noise-free pulses. The network is trained on s…
Generalized local frame transformation theory for ultralong-range Rydberg molecules
P. Giannakeas, Matthew T. Eiles, F. Robicheaux +1
A detailed theoretical framework for highly excited Rydberg molecules is developed based on the generalized local frame transformation. Our approach avoids the use of pseudopotenti…
Proper time delays measured by optical streaking
Ulf Saalmann, Jan M Rost
The generation of a streaking spectrogram is based on energy absorption from the streaking laser. Investigating this absorption we show rigorously under which condition the measure…
Ring Rydberg Composites
Matthew T. Eiles, Andrew L. Hunter, Jan M. Rost
The properties and behaviour of a Ring Rydberg Composite are explicated. This system consists of a ring of ground state atoms centered on a Rydberg atom, whose electron elastically…
Rydberg Composites
Andrew L. Hunter, Matthew T. Eiles, Alex Eisfeld +1
We introduce the Rydberg Composite, a new class of Rydberg matter where a single Rydberg atom is interfaced with a dense environment of neutral ground state atoms. The properties o…
High Harmonic Generation with Twisted Electrons
Sebastian Gemsheim, Jan-Michael Rost
We present analytically and numerically the spectrum of high harmonic emission generated by twisted electrons in the presence of linearly polarized light. Ensuing transitions from…
Purifying electron spectra from noisy pulses with machine learning using synthetic Hamilton matrices
Sajal Kumar Giri, Ulf Saalmann, Jan M. Rost
Photo-electron spectra obtained with intense pulses generated by free-electron lasers through self-amplified spontaneous emission are intrinsically noisy and vary from shot to shot…
Adiabatic passage to the continuum
Ulf Saalmann, Sajal Kumar Giri, Jan M. Rost
We demonstrate that by changing the direction of the chirp in VUV pulses one can switch between excitation and ionization with very high contrast, if the carrier frequency of the l…
Polyatomic trilobite Rydberg molecules in a dense random gas
Perttu J. J. Luukko, Jan-Michael Rost
Trilobites are exotic giant dimers with enormous dipole moments. They consist of a Rydberg atom and a distant ground-state atom bound together by short-range electron-neutral attra…
Rydberg Aggregates
S. Wüster, J. -M. Rost
We review Rydberg aggregates, assemblies of a few Rydberg atoms exhibiting energy transport through collective eigenstates, considering isolated atoms or assemblies embedded within…
Recovery of dynamic interference
Mehrdad Baghery, Ulf Saalmann, Jan M. Rost
We develop general quantitative criteria for dynamic interference, a manifestation of double-slit interference in time which should be realizable with brilliant state-of-the-art hi…
Multi-Manifold Stark Splittings Lift the Rydberg Blockade
Yurii V. Dumin, Jan M. Rost
The spatial evolution of the Rydberg blockade is studied taking into account Stark-split energy levels across several manifolds. We find that the unexpected restoration of a blocka…
Exciton induced directed motion of unconstrained atoms in an ultracold gas
K. Leonhardt, S. Wüster, J. M. Rost
We demonstrate that through localised Rydberg excitation in a three-dimensional cold atom cloud atomic motion can be rendered directed and nearly confined to a plane, without spati…
Dynamical characteristics of Rydberg electrons released by a weak electric field
Elias Diesen, Ulf Saalmann, Martin Richter +3
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 s…
The envelope Hamiltonian for electron interaction with ultrashort pulses
Koudai Toyota, Ulf Saalmann, Jan M. Rost
For ultrashort VUV pulses with a pulse length comparable to the orbital time of the bound electrons they couple to we propose a simplified envelope Hamiltonian. It is based on the…