2008/01/01 by Claudius Riek, Denis V. Seletskiy, A. S. Moskalenko +10 · 3 citations
Engineering · Environmental Science · Physics and Astronomy · #Advanced Machining and Optimization Techniques #Advanced Thermodynamics and Statistical Mechanics #Classical mechanics #Electromagnetic field #Field (mathematics) #Humanities #Laser #Philosophy #Physics #QED vacuum #Quantum #Quantum Electrodynamics and Casimir Effect #Quantum electrodynamics #Quantum fluctuation #Quantum mechanics #Smart Materials for Construction #Thermal Radiation and Cooling Technologies #Ultrashort pulse #Ultrasonics and Acoustic Wave Propagation #Vacuum energy #Vacuum state
paper · open access · doi:10.1126/science.aac9788
published in Cemento Hormigón 350(911), 22-41 (American Association for the Advancement of Science)
openalex publication_date 2008/01/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
The ground state of quantum systems is characterized by zero-point motion. This motion, in the form of vacuum fluctuations, is generally considered to be an elusive phenomenon that manifests itself only indirectly. Here, we report direct detection of the vacuum fluctuations of electromagnetic radiation in free space. The ground-state electric-field variance is inversely proportional to the four-dimensional space-time volume, which we sampled electro-optically with tightly focused laser pulses lasting a few femtoseconds. Subcycle temporal readout and nonlinear coupling far from resonance provide signals from purely virtual photons without amplification. Our findings enable an extreme time-domain approach to quantum physics, with nondestructive access to the quantum state of light. Operating at multiterahertz frequencies, such techniques might also allow time-resolved studies of intrinsic fluctuations of elementary excitations in condensed matter.