2016/05/02 by K. E. Echternkamp, Katharina E. Echternkamp, Armin Feist +2 · 1 citation
Biochemistry, Genetics and Molecular Biology · Chemistry · Physics and Astronomy · #Advanced Electron Microscopy Techniques and Applications #Atomic physics #Attosecond #Chemistry #Coherent control #Coherent spectroscopy #Dephasing #Electron #Free electron model #Laser #Laser-Matter Interactions and Applications #Optics #Physics #Polarization (electrochemistry) #Quantum #Quantum mechanics #Spectroscopy #Spectroscopy and Quantum Chemical Studies #Ultrashort pulse #physics.optics
paper · pdf · doi:10.1038/nphys3844
published as Nature Phys 12 (2016) 1000-1004
arxiv created 2016/05/02 · openalex publication_date 2016/08/15 · arxiv updated 2020/06/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Interference between multiple distinct paths is a defining property of quantum physics, where "paths" may involve actual physical trajectories, as in interferometry, or transitions between different internal (e.g. spin) states, or both. A hallmark of quantum coherent evolution is the possibility to interact with a system multiple times in a phase-preserving manner. This principle underpins powerful multi-dimensional optical and nuclear magnetic resonance spectroscopies and related techniques, including Ramsey's method of separated oscillatory fields used in atomic clocks. Previously established for atomic, molecular and quantum dot systems, recent developments in the optical quantum state preparation of free electron beams suggest a transfer of such concepts to the realm of ultrafast electron imaging and spectroscopy. Here, we demonstrate the sequential coherent interaction of free electron states with two spatially separated, phase-controlled optical near-fields. Ultrashort electron pulses are acted upon in a tailored nanostructure featuring two near-field regions with anisotropic polarization response. The amplitude and relative phase of these two near-fields are independently controlled by the incident polarization state, allowing for constructive and destructive quantum interference of the subsequent interactions. Future implementations of such electron-light interferometers may yield unprecedented access to optically phase-resolved electronic dynamics and dephasing mechanisms with attosecond precision.