Periodic Reporting for period 3 - ATTO-GRAM (Attosecond Gated Holography)
Okres sprawozdawczy: 2023-01-01 do 2024-06-30
Strong-field-driven electric currents in condensed-matter systems open new frontiers in manipulating electronic and optical properties on petahertz frequency scales. While petahertz spectroscopy and control of condensed-matter systems holds great potential, revealing the underlying attosecond (1 attosecond – 10-18 second) dynamics of electrons in solids is still in its infancy. ATTOGRAM addresses this challenge by developing of a state-of-the-art attosecond metrology scheme that integrates the concept of holography with attosecond measurements. The main goals of ATTOGRAM is to reveal ultrafast dynamics of solids as well as fundamental quantum phenomena that have been so far hidden. In addition, ATTOGRAM will open new routes in the establishment of compact solid-state extreme ultraviolet sources, petahertz electronics and optically induced metamaterials.
The main goal in the first phase of the project focused on the establishment of attosecond gated holography as a state-of-the art experimental scheme. During the first stage of the project, we have achieved several important breakthroughs in the development of this scheme and its application in attosecond metrology, revealing fundamental phenomena in atomic and solid state systems.
The first study focuses on the establishment of attosecond gated holography. We have demonstrated this scheme in gas phase systems and probed one of the most fundamental quantum mechanical phenomena -- field induced tunneling. Applying this scheme enabled us to probe the evolution of an electronic wavefunction under the tunneling barrier, and record the phase acquired by an electron as it propagates in a classically forbidden region. We identified the quantum nature of the electronic wavepacket and captured its evolution in complex time and momentum, within a fraction of an optical cycle. The apparatus, developed in this study will be the main experimental set-up for the following stages of the project.
The second study establishes attosecond interferometry in molecular systems. By controlling strong-field-driven electron trajectories we have induced an interferometer on a microscopic level. This scheme recovers the symmetry and structure of molecular orbitals. Zooming into one of the most fundamental strong-field phenomena—field induced tunnel ionization—we reconstructed the angle at which the electronic wavefunction tunnels through the barrier and followed its evolution with attosecond precision.
The third study focuses on attosecond gating in condense matter systems, revealing dynamical band structure. Intense light-matter interaction induces significant modifications of electronic and optical properties, and is certain to dramatically modify the band structure of the light-dressed crystal. Yet, identifying and characterizing such modifications remains an outstanding problem. We applied attosecond gating and addressed this fundamental question, probing laser-induced closing of the band-gap between adjacent conduction bands. Our work revealed the link between extreme nonlinear light matter interactions in strongly driven crystals to the sub-cycle modifications in their effective band structure.
The first study focuses on the establishment of attosecond gated holography. We have demonstrated this scheme in gas phase systems and probed one of the most fundamental quantum mechanical phenomena -- field induced tunneling. Applying this scheme enabled us to probe the evolution of an electronic wavefunction under the tunneling barrier, and record the phase acquired by an electron as it propagates in a classically forbidden region. We identified the quantum nature of the electronic wavepacket and captured its evolution in complex time and momentum, within a fraction of an optical cycle. The apparatus, developed in this study will be the main experimental set-up for the following stages of the project.
The second study establishes attosecond interferometry in molecular systems. By controlling strong-field-driven electron trajectories we have induced an interferometer on a microscopic level. This scheme recovers the symmetry and structure of molecular orbitals. Zooming into one of the most fundamental strong-field phenomena—field induced tunnel ionization—we reconstructed the angle at which the electronic wavefunction tunnels through the barrier and followed its evolution with attosecond precision.
The third study focuses on attosecond gating in condense matter systems, revealing dynamical band structure. Intense light-matter interaction induces significant modifications of electronic and optical properties, and is certain to dramatically modify the band structure of the light-dressed crystal. Yet, identifying and characterizing such modifications remains an outstanding problem. We applied attosecond gating and addressed this fundamental question, probing laser-induced closing of the band-gap between adjacent conduction bands. Our work revealed the link between extreme nonlinear light matter interactions in strongly driven crystals to the sub-cycle modifications in their effective band structure.
In the next phase of the project we will integrate attosecond holography with attosecond gating. The gating measurement will reveal the multi-dimensional nature of the phenomena and probe its instantaneous sub-cycle evolution. The holographic measurement will resolve the complete optical information encoded in the attosecond pulses – both the spectral amplitude and the spectral phase. This scheme will enable us to probe the strong-field interaction while reading the coherence of the induced dynamics via holography. We will apply this scheme to study fundamental phenomena in condence matter systems. Attosecond gated holography will enable us to zoom into the optical cycle and follow the instantaneous modifications of the multiband structure within the optical cycle. The holographic measurement will be an essential step in revealing the primary channels of the interaction. The phase information will provide access into the bands’ symmetry properties, as well as their coupling or decoherence mechanisms. We will be able to obtain direct insight into the internal dynamics and probe the complex quantum wavefunction as it follows the sub-cycle modification of the band structure.