Studying Quantum Mechanics in the Time Domain

22 Aug 2011, 08:00 → 16 Sept 2011, 18:00 Europe/Stockholm

Esa Räsänen (University of Jyväskylä), Eva Lindroth (Stockholm Univ.), Jan Petter Hansen (Bergen Univ.)

NORDITA PROGRAM IN STOCKHOLM, SWEDEN

Stockholm, Sweden (photos: Alexander Dokukin, Ulf Hinds, Jeppe Wikström)

News

A few pictures taken by Ville Kotimäki on Sep 8-9 can be found here.

Several presentations given in the program are now available in PDF here. Please send your talks to Esa, erasanen@jyu.fi. The files will be removed from the website at the end of September.

We are happy to have 59 participants in the program and we cordially welcome everyone to Stockholm!
For your arrival, please find here some important links and documents:

• Welcome letter from Nordita with important administrative information
• Directions from the Airport to City Center and to Nordita / BizApartments with maps, and information about the public transport in Stockholm
• Daily chart of participants

If you have any troubles with directions etc. during your arrival, please contact Eva Lindroth, +46-(0)8-5537-8616.

Nordita is located in a smaller building just in front of the large AlbaNova University Centre, 100 meters from the bus stop Ruddammen. The talks at the kick-off meeting on Aug 22-24 (see the program below) will take place in lecture halls in AlbaNova. The Registration is at the main entrance at AlbaNova (the big Rotunda) on Monday Aug 22 at 10.00-12.00 and then again from 13.00. The Program starts 13.45 in the Oskar Klein Auditorium, one staircase down from the entrance.

Bus timetables:
Bus 72 from BizApartment to Östra Station (PDF) (~10 min walking distance to Nordita)
Bus 44 from Östra Station to Nordita (PDF)
Bus 44 from Nordita to Karlaplan (PDF) (~15 min walking distance to Biz)
Bus 72 from Valhallavägen to Bizapartment (PDF) (note: runs only until ~7pm)
For a detailed map of bus routes, see this link.

On Saturday Aug 27 we organize a boat trip to Sandhamn - a settlement located on the island Sandön ("Sand Island"). The trip is free (apart from lunch etc.) for participants and their family members. We will meet on Saturday morning at 9:15 -- please check the map of the meeting point and detailed information here.

Stockholm and areas near Nordita offer several opportunities for exercising. There are excellent running and walking routes in parks south from BizApartment and north from Nordita. There is a gym SATS located in the same building with BizApartment.

We wish you a pleasurable stay and hope to meet you soon!

Scope

The aim of this Nordita program is to study quantum control and dynamics of few-particle systems in an active collaborative effort between experimentalists and theorists, as well as between recognized senior researchers and young investigators. The activity is motivated by recent advances in the physics of ultrafast phenomena in the femto- and attosecond time scale -- a regime within reach of novel light sources. New insights into fundamental many-body physics are expected when ultrafast atomic and solid-state processes can be monitored in real time.

The topics of the program include, e.g., new light sources such as free-electron lasers and their capabilities, theory and computation of few-particle dynamics, quantum optimal control theory, and interaction of atoms, molecules, and clusters with ultrashort and intense XUV and X-ray pulses. The format of the program supports new collaborative innovations in these fields.

Please see also the related Nordforsk Network as well as the COST Action.

The program will consist of a kick-off meeting, working period, and conference as follows:

Time	Activity	Scope
Aug. 22 – Aug. 25	Kick-off meeting	Keynote talks on the status of the field with a particular emphasis on experiments [Program in PDF]
Aug. 26 – Sep. 9	Workshop	Working in groups, discussions, informal talks, new collaborations. See "Timetable" on the left for a detailed schedule.
Sep. 12 – Sep. 16	Focus week	International conference summarizing the efforts of the Nordita program. NOTE: Organized in combination with the WG1 workshop of the COST Action CM0702, Chemistry with Ultrashort Pulses and Free-Electron Lasers: Looking for Control Strategies Through "Exact" Computations (CUSPFEL) [Program in PDF]

Registration for the program has been closed.

agenda program.pdf

Monday, 22 August

10:00 → 20:30 Kick-off meeting

10:00 → 12:00 Registration

12:00 → 13:00 Lunch

13:00 → 13:45 Registration

13:45 → 14:00 Welcome!

14:00 → 15:00 Spectroscopy with attosecond time resolution

Electronic motion is a key process in a wide range of modern technologies, including micro- to nano-electronics, photovoltaics, bioinformatics, molecular biology, and medical as well as information technologies. The atomic-scale motion of electrons typically unfolds within tens to thousands of attoseconds (1 attosecond [as] = 10^-18 s). Recent advances in laser science have opened the door to watching and controlling these hitherto inaccessible microscopic dynamics [1]-[14]. Key tools include waveform-controlled few-cycle laser light and attosecond extreme ultraviolet pulses. They permit control of atomic-scale electric currents just as microwave fields control currents in nanometer-scale semiconductor chips. By analogy to microwave electronics, we have dubbed this new technology "lightwave electronics" [10,12]. Lightwave electronics provides - for the first time - real-time access to the motion of electrons on atomic and sub-atomic scales. Insight into and control over microscopic electron motion are likely to be important for developing brilliant sources of X-rays, understanding molecular processes relevant to the curing effects of drugs, the transport of bioinformation, or the damage and repair mechanisms of DNA, at the most fundamental level, where the borders between physics, chemistry and biology disappear. Once implemented in condensed matter, the new technology will be instrumental in advancing electronics and electron-based information technologies to their ultimate speed: from microwave towards lightwave frequencies.
[1] M. Hentschel et al., Nature 414, 509 (2001)
[2] R. Kienberger et al., Science 291, 1923 (2002)
[3] A. Baltuska et al., Nature 421, 611 (2003)
[4] R. Kienberger et al., Nature 427, 817 (2004)
[5] E. Goulielmakis et al., Science 305, 1267 (2004)
[6] M. Drescher et al., Nature 419, 803 (2002)
[7] M. Uiberacker et al., Nature 446, 627 (2007)
[8] M. Kling et al., Science 312, 246 (2006)
[9] A. Cavalieri et al., Nature 449, 1029 (2007)
[10] E. Goulielmakis et al., Science 317, 769 (2007)
[11] E. Goulielmakis et al., Science 320, 1614 (2008)
[12] F. Krausz, M. Ivanov, Rev. Mod. Phys. 81, 163 (2009).
[13] M. Schultze et al., Science 328, 1658 (2010). E. Goulielmakis et al., Nature 466, 739 (2010).

Speaker: Ferenc Krausz (MPI Garching)

15:00 → 15:30 Coffee

15:30 → 16:30 Attosecond Physics using Attosecond pulse trains

Speaker: Anne L'Huillier (Lund University)

16:30 → 17:30 Ultra-fast dynamics: Pump-Probe Experiments at FELs

Speaker: Joachim Ullrich (MPI Heidelberg)

17:30 → 20:30 Welcome Reception at Nordita

Tuesday, 23 August

10:00 → 11:00 Attoclock reveals tunnel delay time and tunnel geometry in strong field ionization

Theoretical models often fail to describe the dynamics due to numerical limitations, and we need to develop better approximate models for the ultrafast dynamics on an atomic scale. Novel time-resolved attosecond streaking techniques such as energy streaking and the attoclock, and in addition more recently interference techniques are currently being applied in an attempt to answer a very fundamental question in quantum mechanics: how fast can light remove a bound electron from an atom or a solid?

We have used the attoclock technique [1] to gain more insight in strong laser field ionization, where a the strong laser field bends the binding potential to emit an electron by tunneling (tunnel ionization). Initially we have measured an instantaneous tunneling delay time in helium [1]. More recently we have confirmed no measurable tunneling delay time over a larger intensity regime with the Keldysh parameter well below unity for the first time (which is actually the real regime of tunneling) and extend our studies to argon with the same outcome with regards to the tunneling delay time [2].

Tunneling is described by three important parameters: tunneling rate, tunneling time and tunnel geometry. While the first two have been discussed widely in the last decades, we have recently determined the tunnel geometry for the first time [2]. The attoclock is a unique tool that directly reveals the tunnel geometry and therefore the more complex electron ion interaction. We show that the Coulomb correction alone is not sufficient and multi-electron effects can be important even for atoms such as argon. Possible systematic errors are eliminated with the attoclock by simply using clockwise and anticlockwise streaking fields. In collaboration with Prof. Lars B. Madsen’s group from Aarhus University we developed a modified semiclassical model that agrees well with our attoclock experiments [2]. The theory represents a "textbook" quality and represents everything a theory has to do: describes the experiment, relies on accurate assumptions, and new effects are clearly identified, stated and quantified. Even more so, the polarizabilities that enters the model are calculated and measured using other independent methods. Attosecond measurements have typically used attosecond streaking techniques for which the detailed electron ion interaction need to be understood on an attosecond time scale. If this interaction is not understood correctly, wrong conclusions could be drawn on possible time delays. To date attosecond streaking has been applied to atomic, molecular or solid target. Multielectron effects as pointed out here are even more important for more complex targets.

[1] P. Eckle, A. Pfeiffer, C. Cirelli, A. Staudte, R. Dörner, H. G. Muller, M. Büttiker, U. Keller, Attosecond ionization and tunneling delay time measurements Science, vol. 322, pp. 1525-1529, 2008
[2] A. N. Pfeiffer, C. Cirelli, M. Smolarski, D. Dimitrovski, M. Abu-samha, L. B. Madsen, U. Keller, Attoclock reveals geometry of laser-induced tunnel ionization arXiv:1103.4803v1 [physics.atom-ph] online 25. March 2011

Speaker: Ursula Keller (ETH Zürich)

10:00 → 19:00 Kick-off meeting

11:00 → 11:30 Coffee

11:30 → 12:30 The Reincarnation of Multiphoton Processes

About fifty years ago, the first laser-induced two-photon absorption in an atomic vapor was observed in Cesium. With the subsequent developments in laser technology, the field of multiphoton (MP) processes evolved through a series of stages, involving harmonic generation, resonantly enhanced multiphoton ionization (REMPI), effects of field correlations in non-linear processes, to mention a few. With the advent of sub-picosecond, Fourier limited and eventually few-cycle sources, over the last 20 years, the paradigm shifted to what is now known as strong field phenomena and attosecond physics, in terms of the single-active electron approximation, dominated by recollision dynamics. Thus multiphoton processes per se went into a dormant stage, leaving behind certain tools such as REMPI. The appearance of strong, sub-picosecond, radiation in a broad frequency range, from the XUV to hard X-rays, has now revived MP concepts and techniques, but in an entirely new context. Whereas traditional MP processes under infrared to UV radiation involved exclusively valence electrons, in the new paradigm it is inner electrons that dominate the chain of events triggered by the exposure to strong, short wavelength radiation.

After a brief historical review of the main stages and concepts of MP processes under long wavelength radiation, I discuss their connection to the short wavelength context, using specific examples of observations in the XUV to soft X-ray range, in order to illustrate the similarities and differences between the two paradigms. In particular the operational meaning of concepts such as strong field, short pulse, sequential versus direct multiple ionization, double resonance, etc. are discussed and illustrated through the application to specific systems.

Speaker: Peter Lambropoulos (University of Crete)

12:30 → 14:30 Lunch

14:30 → 15:30 Attosecond molecular spectroscopies with XUV harmonic radiation

Speaker: Alfred Maquet (UPMC Paris)

15:30 → 16:00 Coffee

16:00 → 17:00 Hole dynamics and coherence

Photoionization of an atom or a molecule leads, in general, to the formation of a superposition of ionic eigenstates. That superposition cannot, in general, be described in terms of a wave function, but a description in terms of a reduced density matrix (a statistical mixture) is required. In the first part of the talk, ultrafast, partially coherent hole dynamics driven by spin-orbit coupling will be analyzed in terms of a time-dependent multichannel mean-field theory [1]. This theory will be compared with the results of an attosecond transient absorption experiment on strong-field-ionized krypton atoms [2]. In the second part of the talk, a new implementation of time-dependent configuration interaction singles (TDCIS) will be discussed [3]. Using TDCIS calculations, it will be shown that photoelectron-mediated interchannel coupling causes ion decoherence in attosecond photoionization. As a consequence, even if the spectral bandwidth of the ionizing pulse exceeds the energy splittings among the hole states involved, perfectly coherent hole wave packets cannot be formed [4]

[1] N. Rohringer and R. Santra, Phys. Rev. A 79, 053402 (2009).
[2] E. Goulielmakis, Z.-H. Loh, A. Wirth, R. Santra, N. Rohringer, V. S. Yakovlev, S. Zherebtsov, T. Pfeifer, A. M. Azzeer, M. F. Kling, S. R. Leone, and F. Krausz, Nature 466, 739 (2010).
[3] L. Greenman, P. J. Ho, S. Pabst, E. Kamarchik, D. A. Mazziotti, and R. Santra, Phys. Rev. A 82, 023406 (2010).
[4] S. Pabst, L. Greenman, P. J. Ho, D. A. Mazziotti, and R. Santra, Phys. Rev. Lett. 106, 053003 (2011).

Speaker: Robin Santra (DESY Hamburg)

17:00 → 19:00 Get together (drinks and snacks) at Nordita

Wednesday, 24 August

10:00 → 22:00 Kick-off meeting

10:00 → 11:00 Pulse Shaping for Coherent Control, 2D Spectroscopy, and Ultrafast Nano-Optics

Shaped femtosecond laser pulses have found applications in many different research areas of the ultrafast sciences. Flexible manipulation of electric-field evolution provides novel opportunities for studying light-matter interaction in various quantum-mechanical systems. This talk provides illustrative examples from coherent control, coherent two-dimensional spectroscopy, and ultrafast nano-optics, with environments ranging from the gas phase over molecules in liquids to solid-state surfaces. Although traditionally there has not been a lot of interaction between the three mentioned research fields, the common theme of shaped pulses can serve as a connecting element, opening new avenues of scientific investigation.

Speaker: Tobias Brixner (University of Würtzburg)

11:00 → 11:30 Coffee

11:30 → 12:30 Analysis and control of electronic motion in the time domain

This lecture is about how electronic motion can be monitored, analyzed and, ultimately, controlled, in real time. In particular: (i) A novel approach to describe electronic transport through single molecules or atomic wires, sandwiched between semi-infinite leads, will be presented. The basic idea is to propagate the time-dependent Kohn Sham equations in time upon ramping up a bias between the metallic leads. In this way, genuinely time-dependent phenomena, not accessible in the standard Landauer approach, can be addressed. For example, employing an Anderson model, we demonstrate that Coulomb blockade corresponds, in the time-domain, to a periodic charging and discharging of the quantum dot [1]. (ii) With modern pulse-shaping facilities, the control of electronic motion is becoming more and more realistic. By combining quantum optimal control theory with TDDFT, we calculate shaped laser pulses suitable to control, e.g., the chirality of currents in quantum rings [2], the location of electrons in double quantum dots, as well as the enhancement of a single peak in the harmonic spectrum of atoms and molecules. (iii) In all practical TDDFT calculations, approximate forms of the exchange-correlation potential need to be employed. One of the most popular approximations, the adiabatic local-density approximation (ALDA) will be analyzed as to whether the main error comes from the adiabaticity assumption, i.e. locality in time, or from the LDA, i.e. locality in space. For an exactly solvable model where the exact adiabatic approximation can be extracted, we find the surprising fact, that the adiabaticity assumption can be an excellent approximation even in highly intense laser fields [3]. (iv) Finally, the coupling between electronic and nuclear motion will be addressed. As a first step towards a full ab-initio treatment of the coupled electron-nuclear motion in time-dependent external fields, we deduce an exact factorization of the complete wavefunction into a purely nuclear part and a many-electron wavefunction which parametrically depends on the nuclear configuration. We derive formally exact equations of motion for the nuclear and electronic wavefunctions [4]. These exact equations lead to a rigorous definition of time-dependent potential energy surfaces as well as time-dependent geometric phases. With the simple example of the hydrogen molecular ion in a laser field we demonstrate the significance of these concepts in understanding the full electron-ion dynamics. In particular, the time-dependent potential energy surfaces are shown to represent a powerful tool to analyse and interpret different (direct vs. tunneling) types of dissociation processes. [1] S. Kurth, G. Stefanucci, E. Khosravi, C. Verdozzi, E.K.U. Gross, Phys. Rev.Lett.104, 236801 (2010). [2] E. Räsänen, A. Castro, J. Werschnik, A. Rubio, E.K.U. Gross, Phys. Rev. Lett. 98,157404 (2007). [3] M. Thiele, E.K.U. Gross and S. Kümmel, Phys. Rev. Lett. 100, 153004 (2008). [4] A. Abedi, N.T. Maitra, E.K.U. Gross, Phys. Rev. Lett. 105, 123002 (2010).

Speaker: E. K. U. Gross (MPI Halle)

12:30 → 14:30 Lunch

14:30 → 15:30 Read-out and coherent control of electron spin qubits in quantum dots

Quantum information processing requires accurate control of the time evolution of physical systems at the level of single quantum mechanical degrees of freedom. I will present our work on the coherent manipulation of individual and coupled electron spins in semiconductor quantum dots, and on independent read-out of the spins.

Speaker: Lieven Vandersypen (TU Delft)

15:30 → 16:00 Coffee

16:00 → 17:00 Exploring few- and many-body physics with frozen Rydberg gases

The investigation of Rydberg atoms has a long history, dating back to the early days of Atomic Physics. Rydberg gases at ultra-low temperatures were first realized only in the last decade by combining advances in atom manipulation and cooling with narrow-band laser excitation of Rydberg states. The exquisite controlof the electronic excitation and the centre-of-mass motion, employing external fields, allows one to exploit the unique and exaggerated properties of Rydberg atoms, namely their large size, large electronic orbiting times, small electronic binding energy, and extremely strong dipole–dipole and van derWaals interactions. The combination of strong atomic interactions and a high level of quantum control, reaching down to the single atom level, gives rise to both new fundamental physics and interesting applications of Rydberg gases, including for example investigations of novel phases of quantum matter, and controlled preparation of atom or photon entanglement. In my presentation I will give a general introduction into the field and discuss some recent experiments of my group.

Speaker: Matthias Weidemüller (University of Heidelberg)

18:00 → 22:00 Dinner at AlbaNova

Thursday, 25 August

10:00 → 11:00 Introduction of the participants

~1-3 min presentation of each participant on the blackboard

14:30 → 15:00 coffee

15:00 → 16:00 Time delay discussion group [see PRL 106, 143002 (2011)]

Please check this paper:
http://prl.aps.org/abstract/PRL/v106/i16/e169904

Friday, 26 August

09:30 → 10:00 coffee

10:00 → 11:00 Talk by Luca Argenti: Vibrationally resolved photoelectron spectroscopy of CH4: Studying electron diffraction from within

14:30 → 15:00 coffee

Saturday, 27 August

09:15 → 18:00 Trip to the Archipelago (Sandhamn) with boat (whole day)

See the main page for further information.

Monday, 29 August

09:30 → 10:00 coffee

10:00 → 10:30 Introduction of the new participants

10:30 → 11:30 Talk (Jan Michael Rost)

14:30 → 15:00 coffee

15:00 → 15:30 Talk by Tobias Kramer: The quantum-classical borderline, from 2 to many electrons

Tuesday, 30 August

09:30 → 10:00 coffee

10:00 → 11:00 Talk by Michael Genkin: Transport through Rydberg aggregates in the blockade regime

We discuss excitation dynamics in Rydberg aggregates, induced by resonant dipole-dipole interactions. In particular, we investigate the possibility to extend recently suggested efficient single-atom transport schemes to Rydberg-blocked atomic clouds.

Wednesday, 31 August

09:30 → 10:00 coffee

10:00 → 11:00 Talk by Maria Richter: Photoelectron spectroscopy of the Kramers-Henneberger atom

Today laser pulses with electric fields comparable to or higher than the electrostatic forces binding valence electrons in atoms and molecules have become a routine tool with applications in laser acceleration of electrons and ions, generation of short wavelength emission from plasmas and clusters, laser fusion, etc. Intense fields are also naturally created during laser filamentation in the air or due to local field enhancements in the vicinity of metal nanoparticles. One would expect that very intense fields would always lead to fast ionization of atoms or molecules. However, recently observed acceleration of neutral atoms [1] at the rate of 1015 m/sec2 when exposed to very intense infrared (IR) laser pulses demonstrated that a substantial fraction of atoms remained stable during the pulse. What is the structure of these exotic laser-dressed atoms surviving super-atomic fields? Can it be directly imaged using modern experimental tools? Using ab-initio calculations for the potassium atom, we show [2] how the electronic structure of these stable "laser-dressed" atoms can be unambiguously identified and imaged in angle resolved photoelectron spectra obtained with standard femtosecond laser pulses and velocity map imaging techniques, see e.g. recent experiments [3,4]. We find that the electronic structure of these atoms follows the theoretical predictions made over 40 years ago by W. Henneberger [5], that have so far remained unconfirmed experimentally and thus not generally accepted. We also show that the so-called Kramers-Henneberger (KH) atom is formed and can be detected even before the onset of the stabilization regime. Our findings open the way for visualizing and controlling bound electron dynamics in strong laser fields and reexamining its role in various strong field processes, including the microscopic description of high order Kerr non-linearities and their role in laser filamentation [6]. 1. Eichmann et al., “Acceleration of neutral atoms in strong short-pulse laser fields”, Nature, 461, 1261-1264 (2009). 2. Felipe Morales, Maria Richter, Serguei Patchkovskii and Olga Smirnova, “Imaging the Kramers-Henneberger atom”, PNAS, accepted. 3. M. Wollenhaupt, M. Krug, J. Köhler, T. Bayer, C. Sarpe-Tudoran and T. Baumert, “Photoelectron angular distributions from strong-field coherent electronic excitation”, Appl. Phys. B, 95, 245 (2009). 4. M. Schuricke, G. Zhu, J. Steinmann, K. Simeonidis, I. Ivanov, A. Kheifets, A. N. Grum-Grzhimailo, K. Bartschat, A. Dorn and J. Ullrich, “ Strong-field ionization of lithium”, Phys. Rev. A, 83, 023413 (2011). 5. W. Henneberger, “Perturbation method for atoms in intense laser fields”, Phys. Rev. Lett., 21, 838 (1968). 6. Béjot et al., “Higher-Order Kerr Terms Allow Ionization-Free Filamentation in Gases”, Phys. Rev. Lett., 104, 103903 (2010).

15:00 → 16:00 Talk by Nicolas Sisourat: Giant interatomic Coulombic decay

Interatomic Coulombic decay (ICD) is an ultrafast non-radiative electronic decay process for excited atoms embedded in a chemical environment. Via ICD, the excited system can get rid of the excess energy and this excess energy is transferred to one of the neighbors and ionizes it. Whereas the same excited atom when isolated relaxes only by emitting a photon in a time range of picoseconds to nanoseconds, ICD takes place in the femtosecond range. Thus, ICD is generally the most favorable decay process. Through ICD, the energy transfer between the two involved atoms can take place over large distances. A question which arises is how far can atoms exchange energy? The giant extremely weakly bound helium dimer is a perfect candidate to investigate this issue. After simultaneous ionization and excitation of one helium atom, the excited ion can relax through ICD and thus ionize the neighboring neutral helium atom. The resulting two He$^+$ then undergo a Coulomb explosion and fly apart. As it will be shown, the two helium atoms can exchange energy via ICD over distances of more than 45 times their atomic radius. Oscillatory structures in the kinetic energy release spectra reflect the nodal structures of vibrational wavefunctions involved in the decay process.

Thursday, 1 September

09:30 → 10:00 coffee

10:00 → 11:00 Talk by Maria Hellgren: Optimal control with time-dependent density-functional theory: First application to the ionization of H2

17:00 → 19:00 Barbeque

Feel free to join the barbeque at Nordita! We have some meat, vegetables, drinks and might bring some surströmming (fermented herring) as well... You can also bring your family members.

Friday, 2 September

10:00 → 11:00 Talk by Luca Argenti: Towards an interferometric spectroscopy of metastable wave packet dynamics

Saturday, 3 September

10:30 → 11:30 Visit to Vasa Museum

Let's meet in front of the museum at 10:20. A guided tour in English starts at 10:30.

Monday, 5 September

10:00 → 11:00 Talk by Adam Etches: Two-centre interference minima in the high-harmonic generation

Tuesday, 6 September

15:00 → 16:00 Talk by Ken Taylor: The R-Matrix incorporating Time propagation (RMT) method for a multi-electron atom in an intense laser field

Wednesday, 7 September

10:00 → 11:00 Talk by Ingo Barth: Non-adiabatic ionization in circularly polarized laser fields

Motivated by the recent experimental work of Goulielmakis et al. on real-time observation of electron motion in the valence 4p shell of krypton atoms [1], we will present the theory for the ionization of arbitrary states of atoms in strong circularly polarized laser fields. It is commonly assumed that strong-field ionization in low-frequency laser field is an adiabatic process. Therefore, one does not expect to generate electronic ring currents in ions during ionization in the low-frequency fields. To check this assumption, we revisit the theory of strong-field ionization developed by Perelomov, Popov, and Terent’ev (PPT) [2,3]. The original PPT theory includes explicit results for ionization of s-orbitals by circularly or in general elliptically polarized laser fields. We extend the PPT approach to p0, p+ and p- orbitals of atoms in circularly polarized field. This allows us to address the question on the asymmetry in ionizing the ring-current carrying p+ and p- orbitals by the right (or left) circular polarization, thus characterizing the currents that can be induced by non-adiabatic ionization. [1] E. Goulielmakis, Z.-H. Loh, A. Wirth, R. Santra, N. Rohringer, V. S. Yakovlev, S. Zherebtsov, T. Pfeifer, A. M. Azzeer, M. F. Kling, S. R. Leone, F. Krausz, Real-time observation on valence electron motion, Nature 466, 739 (2010) [2] A. M. Perelomov, V. S. Popov, M. V. Terent’ev, Ionization of atoms in an alternating electric field, Soviet Physics JETP 23, 924 (1966)

Thursday, 8 September

10:00 → 11:00 Talk by Armin Scrinzi: What to watch out for when you really do exterior complex scaling

17:00 → 21:00 Barbeque

Feel free to join the barbeque at Nordita! We have some meat, vegetables, drinks and might bring some surströmming (fermented herring) as well... You can also bring your family members.

Friday, 9 September

10:00 → 11:00 Talk by Ulf Saalmann: Non-adiabatic electron pumps: Rectification and current reversals

Adiabatic electron pumps have been theoretically proposed and experimentally realized some time ago. Here, non-adiabatic effects are discussed. It will be shown that one can control the direction of the induced current by changing the driving frequency. This surprising observation is related to a rectification effect in the non-adiabatic regime.

Monday, 12 September

12:00 → 13:00 Lunch

13:15 → 14:30 CM0702 COST ACTION WORKSHOP WG1 (Attoscience I)

13:15 → 14:00 Trends in attoscience-theory perspectives

Speaker: Lars Bojer Madsen (University of Århus)

14:00 → 14:30 Quantum interferences in attophysics

Speaker: Marcus Dahlström (Lund University)

14:30 → 15:00 coffee break

15:00 → 17:30 CM0702 COST ACTION WORKSHOP WG1 (Molecules)

15:00 → 15:30 High-harmonic generation from polar molecules

Speaker: Adam Etches (University of Århus)

15:30 → 16:00 Stark shifts and multielectron polarization effects in atoms and molecules

Speaker: Darko Dimitrovski (University of Århus)

16:00 → 16:30 coffee break

16:30 → 17:00 Time-dependent description of the electronic predissociation in the LiH molecule

Speaker: Patryk Jasik (Gdansk University of Technology)

17:00 → 17:30 Reactions involving antihydrogen

Speaker: Svante Jonsell (Stockholm University)

Tuesday, 13 September

09:15 → 10:00 Attosecond electron interferometry

Speaker: Johan Mauritsson (Lund University)

09:15 → 12:00 CM0702 COST ACTION WORKSHOP WG1 (Attoscience II)

10:00 → 10:30 Massively parallel ionization in ultra-short pulses

Speaker: Ulf Saalmann (MPI Dresden)

10:30 → 11:00 coffee break

11:00 → 11:30 Ionization by intense and short electric pulses - classical picture

Speaker: Karoly Tokesi

11:30 → 12:00 Propagation of strong XFEL pulses

Speaker: Faris Gelmukhanov (Stockholm University)

12:00 → 13:00 Lunch

13:00 → 15:00 Discussion / Workshops

15:00 → 17:30 CM0702 COST ACTION WORKSHOP WG1 (Time-resolved Ionization)

15:00 → 15:30 Ionization in strong IR pulses: yields, photo-electron momentum spectra, and attosecond-XUV probing of the process

Speaker: Armin Scrinzi (LMU Munich)

15:30 → 16:00 Simulations on pump and probe experiments on Neon

Speaker: Thomas Carette (Stockholm University)

16:00 → 16:30 coffee break

16:30 → 17:00 One-and two-photon double ionization of atoms: Identifying the mechanisms

Speaker: Morten Førre (University of Bergen)

Wednesday, 14 September

09:15 → 12:00 CM0702 COST ACTION WORKSHOP WG1 (Strong Fields / Correlated Systems I)

09:15 → 10:00 Multi-electron response of atoms to intense laser light

Speaker: Ken Taylor (Queen's University)

10:00 → 10:30 Accurate numerical methods for explicit time-dependent Hamiltonians

Speaker: Hans Karlsson (Uppsala University)

10:30 → 11:00 coffee break

11:00 → 11:30 Time scaling with high order time-propagation techniques to solve the time-dependent Schrödinger equation (Part I)

Speaker: Johannes Eiglsperger (University of Regensburg)

11:30 → 12:00 Time scaling with high order time-propagation techniques to solve the time-dependent Schrödinger equation (Part II)

Speaker: Bernard Piraux (Univ. Catholique de Louvain)

12:00 → 13:00 Lunch

13:00 → 15:00 Discussion / Workshops

15:00 → 15:30 Above threshold ionization of hydrogen atom and molecular ion by laser pulse

Speaker: Renata Della Picca (UPMC)

15:00 → 17:30 CM0702 COST ACTION WORKSHOP WG1 (Strong Fields / Correlated Systems I)I

15:30 → 16:00 Two-photon double ionization studies in noble gases. A time-dependent density matrix approach of the direct/sequential problem

Speaker: Damien Middleton (Dublin City University)

16:00 → 16:30 coffee break

16:30 → 17:00 Circular Rydberg states in circularly polarized laser fields

Speaker: Sigurd Askeland (University of Bergen)

17:00 → 17:30 Electron-energy bunching in laser-driven soft recollisions

Speaker: Alexander Kästner (MPI Dresden)

Thursday, 15 September

09:15 → 12:00 CM0702 COST ACTION WORKSHOP WG1 (Complex Systems and Methods)

09:15 → 10:00 From few to many-body dynamics: interacting electrons in magnetic fields

Speaker: Tobias Kramer (University of Regensburg)

10:00 → 10:00 Unbound systems: Studying what remains rather than what escapes

Speaker: Sølve Selstø (Oslo University College)

10:30 → 11:00 coffee break

11:00 → 11:30 Coherence Distillation

Speaker: Alejandro Saenz (Humboldt University Berlin)

11:30 → 12:00 Parallel implementation of the TDSE using GPUs

Speaker: Cathal O'Broin (Dublin City University)

12:00 → 13:00 Lunch

13:00 → 15:00 Discussion / Workshops

15:00 → 18:00 CM0702 COST ACTION WORKSHOP WG1 (Closing and Outlook)

15:00 → 15:45 Towards zeptosecond time resolution through interference in quasi-molecular radiation

Speaker: Reinhold Schuch (Stockholm University)

15:45 → 18:00 Reports from the Nordita Workshop: New findings and directions

18:00 → 21:30 Workshop dinner