Interpreting Attoclock Measurements of Tunnelling Times
Lisa TorlinaFelipe MoralesJivesh KaushalH. G. MullerИ. А. ИвановA. S. KheifetsAlejandro ZielinskiArmin ScrinziSuren SukiasyanMisha IvanovOlga Smirnova
0
Citation
0
Reference
10
Related Paper
Abstract:
Resolving in time the dynamics of light absorption by atoms and molecules, and the electronic rearrangement this induces, is among the most challenging goals of attosecond spectroscopy. The attoclock is an elegant approach to this problem, which encodes ionization times in the strong-field regime. However, the accurate reconstruction of these times from experimental data presents a formidable theoretical challenge. Here, we solve this problem by combining analytical theory with ab-initio numerical simulations. We apply our theory to numerical attoclock experiments on the hydrogen atom to extract ionization time delays and analyse their nature. Strong field ionization is often viewed as optical tunnelling through the barrier created by the field and the core potential. We show that, in the hydrogen atom, optical tunnelling is instantaneous. By calibrating the attoclock using the hydrogen atom, our method opens the way to identify possible delays associated with multielectron dynamics during strong-field ionization.Keywords:
Attosecond
Hydrogen atom
Tunnel ionization
To measure and control the electron motion in atoms and molecules by the strong laser field on the attosecond time scale is one of the research frontiers of atomic and molecular photophysics. It involves many new phenomena and processes and raises a series of questions of concepts, theories and methods. Recent studies show that the Coulomb potential can cause the ionization time lag (about 100 attoseconds) between instants of the field maximum and the ionization-rate maximum. This lag can be understood as the response time of the electronic wave function to the strong-field-induced ionization event. It has a profound influence on the subsequent ultrafast dynamics of the ionized electron and can significantly change the time-frequency properties of electron trajectory (an important theoretical tool for attosecond measurement). Here, the research progress of response time and its implications on attosecond measurement are briefly introduced.
Attosecond
Tunnel ionization
Cite
Citations (0)
In this paper we measured an "instantaneous" intensity independent tunneling delay time with an upper limit of 12 as [3]. Our experiments have given us direct access to the tunneling delay time with an unprecedented time accuracy of a few tens of attoseconds using attosecond angular streaking. Our results give strong indication that there is no real tunneling delay time and we expect that this will shed some light on the ongoing theoretical discussion on tunneling time and tunnel ionization in strong field physics.
Streaking
Attosecond
Tunnel ionization
Cite
Citations (0)
We use attosecond angular streaking to place an intensity-averaged upper limit of 12 attoseconds on the tunneling delay time in strong field ionization of a helium atom. This is much shorter than the Keldysh time.
Streaking
Attosecond
Helium atom
Double ionization
Tunnel ionization
Cite
Citations (0)
One of the fundamental processes in nature is the photoelectric effect in which an electron is ripped away from its atom via the interaction with a photon. This process was long believed to be instantaneous but with the development of attosecond pulses (1 as 10−18 s) we can finally get an insight into its dynamic. Here we measure a delay in ionization time between two differently bound electrons. The outgoing electrons are created via ionization with a train of attosecond pulses and we probe their relative delay with a synchronized infrared laser. We demonstrate how this probe field influences the measured delays and show that this contribution can be estimated with a universal formula, which allows us to extract field free atomic data.
Attosecond
Photoelectric effect
Tunnel ionization
Double ionization
Atomic units
Cite
Citations (0)
Tunneling ionization is a basic process of strong-field atomic physics. Revealing its time-resolved dynamics is one of the goals of attosecond science. Here, we show that after tunneling, a finite response time (about 100 attoseconds) is needed for the electronic state to evolve into an ionized state. We construct a semiclassical model with a compact expression to describe this response time. With this expression, a simple Coulomb-calibrated mapping relation between time and observables is obtained. Comparisons with experiments give direct evidence for our theory. Our work uncovers the transient response process around tunnel exit and provides a simple tool for quantitatively explaining and predicting experimental phenomena in attosecond measurements.
Attosecond
Semiclassical physics
Tunnel ionization
Cite
Citations (2)
To measure and control the electron motion in atoms and molecules by the strong laser field on the attosecond time scale is one of the research frontiers of atomic and molecular photophysics. It involves many new phenomena and processes and raises a series of questions of concepts, theories and methods. Recent studies show that the Coulomb potential can cause the ionization time lag (about 100 attoseconds) between instants of the field maximum and the ionization-rate maximum. This lag can be understood as the response time of the electronic wave function to the strong-field-induced ionization event. It has a profound influence on the subsequent ultrafast dynamics of the ionized electron and can significantly change the time-frequency properties of electron trajectory (an important theoretical tool for attosecond measurement). Here, the research progress of response time and its implications on attosecond measurement are briefly introduced.
Attosecond
Tunnel ionization
Cite
Citations (0)
Attosecond
Tunnel ionization
Cite
Citations (866)
All aspects of attosecond technology rely on electron wavepackets formed by ionization and controlled by strong laser fields. When the electron wavepacket is formed by tunnel ionization in linearly polarized light, attosecond electron or optical pulses can be produced, both of which will play significant rolls in attosecond spectroscopy. When the electron wavepacket is formed by an attosecond x-ray pulse, the x-ray pulse can be fully characterized by using a strong laser field. If an atomic, molecular or nuclear dynamic processes form correlated wavepackets, the decay dynamics can be measured with attosecond precision.
Attosecond
Tunnel ionization
Cite
Citations (2)
We observe an optical signature induced by sub-cycle modulation of the free carrier density in several transparent dielectrics, quasi-periodically ionized on an attosecond time scale by electric field peaks of a focused few-cycle laser pulse.
Attosecond
Tunnel ionization
Modulation (music)
Cite
Citations (0)
To measure and control the electron motion in atoms and molecules by the strong laser field on the attosecond time scale is one of the research frontiers of atomic and molecular photophysics. It involves many new phenomena and processes and raises a series of questions of concepts, theories and methods. Recent studies show that the Coulomb potential can cause the ionization time lag (about 100 attoseconds) between instants of the field maximum and the ionization-rate maximum. This lag can be understood as the response time of the electronic wave function to the strong-field-induced ionization event. It has a profound influence on the subsequent ultrafast dynamics of the ionized electron and can significantly change the time-frequency properties of electron trajectory (an important theoretical tool for attosecond measurement). Here, the research progress of response time and its implications on attosecond measurement are briefly introduced.
Attosecond
Tunnel ionization
Cite
Citations (0)