Attosecond Double-Slit Experiment

Abstract

A new scheme for a double-slit experiment in the time domain is presented. Phase-stabilized few-cycle laser pulses open one to two windows ("slits") of attosecond duration for photoionization. Fringes in the angle-resolved energy spectrum of varying visibility depending on the degree of whichway information are observed. A situation in which one and the same electron encounters a single and a double slit at the same time is discussed. The investigation of the fringes makes possible interferometry on the attosecond time scale. The number of visible fringes, for example, indicates that the slits are extended over about 500 as.The conceptually most important interference experiment is the double-slit scheme, which has played a pivotal role in the development of optics and quantum mechanics. In optics its history goes back to Young's double-slit experiment. Its scope was greatly expanded by Zernike's work and continues to deliver new insights into coherence to the present day [1]. One of the key postulates of quantum theory is interference of matter waves, experimentally confirmed by electron diffraction [2,3]. More than 30 years later, Jönsson was the first to perform a double-slit experiment with electrons [4]. Of particular importance for interpreting quantum mechanics have been experiments with a single particle at any given time in the apparatus [5,6]. More recent work has illuminated the fundamental importance of complementarity in which-way experiments [7] and of quantum information in quantum-eraser schemes [8].In this letter a novel realization of the double-slit experiment is described. It is distinguished from conventional schemes by a combination of characteristics: (i) The double slit is realized not in position-momentum but in time-energy domain.(ii) The role of the slits is played by windows in time of attosecond duration. (iii) These "slits" can be opened or closed by changing the temporal evolution of the field of a few-cycle laser pulse. (iv) At any given time there is only a single electron in the double-slit arrangement. (v) The presence and absence of interference are observed for the same electron at the same time.Interference experiments in the time-energy domain are not entirely new. Interfering electron wave packets were created by femtosecond laser pulses [9]. Accordingly, the windows in time (or temporal slits) during Temporal variation of the electric field E (t) = E0(t) cos(ωt + ϕ) of few-cycle laser pulses with phase ϕ = 0 ("cosine-like") and ϕ = −π/2 ("sine-like"). In addition, the field ionization probability R(t), calculated at the experimental parameters, is indicated. Note that an electron ionized at t = t0 will not necessarily be detected in the opposite direction of the field E at time t0 due to deflection in the oscillating field.which these wave packets are launched were comparable to the pulse duration. In the present experiment, in contrast, the slits are open during a small fraction of an optical cycle, which gives the attosecond width. A number of experiments, in particular...

Attosecond electron wave packet interferometry

“…An additional interference structure is superposed on that described previously, which consists of circles centred at the origin, simply expressing energy conservation. This interference effect is very similar to that leading to electron peaks separated byhω, when atoms are ionized by intense laser pulses 23,24 . In addition, argon has three different initial states, 3p, m = 0,±1 and, for one-photon absorption, several possible final states with s or d symmetry.…”

MAKING OPTICAL WAVES, TRACING ELECTRONS IN REAL-TIME: THE ONSET OF THE ATTOSECOND REALM (Invited Review)

“…The precisely controllable CEP of a near-infrared driving waveform could be used to adjust both the ionization yield [28] in each field half-cycle and the classical excursion of the ionized electron in the continuum to generate, upon recombination with the parent ion, single or twin soft x-ray attosecond bursts of radiation near the cutoff of the emitted spectra. This first essential paradigm of attosecond control was followed by equally crisp demonstrations of strong-field controlled electron emission from atoms [29,30], their double ionization [31], the sub-cycle control and the dissociation in simple molecular species [32]. More recently, this paradigm was further extended to field sensitive control of chemical dynamics in more Figure 2.…”

The impact of the carrier envelope phase-dependence on system and laser parameters

“…Theoretical calculations have shown that the (high energy) parts of PES coming from electron recollisions are more sensitive to CEP than the (low energy) parts from directly emitted electrons [15,12,16,17,18]. Experimentally, the dependence of high-energy PES on the CEP has been explored for atoms [13,19,20], dimer molecules [21], and nano-tips [22,23], providing challenging motivations for the theoretical investigations.…”