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.
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http://dx.doi.org/10.1126/science.aac9788 | DOI Listing |
Food Chem X
January 2025
College of Food and Biological Engineering, Chengdu University, Chengdu 610106, PR China.
Tender ginger is often used a fresh vegetable but hard to storage due to the delicate skin, high moisture content and prone to spoilage. In order to develop suitable preservation technology for tender ginger, the effects of vacuum packaging combined with different preservation temperatures (20-25 °C room temperature, 4 °C and 10 °C) on tender ginger shelf life were investigated. The results indicated that vacuum packaging combined with 4 °C (VP4) preservation could easily cause cold damage and postharvest physiological fluctuations.
View Article and Find Full Text PDFSci Rep
January 2025
Science and Technology on Vacuum and Physics Laboratory, Lanzhou Institute of Physics, Lanzhou, 730000, China.
The Laser Interferometer Space Antenna (LISA) mission is designed to detect space gravitational wave sources in the millihertz band. A critical factor in the success of this mission is the residual acceleration noise metric of the internal test mass (TM) within the ultra-precise inertial sensors. Existing studies indicate that the coupling effects of residual gas and temperature gradient fluctuations significantly influence this metric, primarily manifesting as the radiometer effect and the outgassing effect.
View Article and Find Full Text PDFJ Proteome Res
January 2025
Omics Technologies, Cellzome a GSK company, Meyerhofstrasse 1, D-69117 Heidelberg, Germany.
Data-independent acquisition (DIA) on ion mobility mass spectrometers enables deep proteome coverage and high data completeness in large-scale proteomics studies. For advanced acquisition schemes such as parallel accumulation serial fragmentation-based DIA (diaPASEF) stability of ion mobility (1/K) over time is crucial for consistent data quality. We found that minor changes in environmental air pressure systematically affect the vacuum pressure in the TIMS analyzer, causing ion mobility shifts.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2025
Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3255, USA.
In this study, a single zirconium carbide (ZrC) nanoneedle structure oriented in the <100> direction was fabricated by a dual-beam focused ion beam (FIB-SEM) system, and its field emission characteristics and emission current stability were evaluated. Benefiting from controlled fabrication with real-time observation, the ZrC nanoneedle has a smooth surface and a tip with a radius of curvature smaller than 20 nm and a length greater than 2 μm. Due to its low work function and well-controlled morphology, the ZrC nanoneedle emitter, positioned in a high-vacuum chamber, was able to generate a single and collimated electron beam with a current of 1.
View Article and Find Full Text PDFJ Chem Phys
January 2025
Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
The quantum-electrodynamic non-adiabatic emission (QED-NAE) is a type of radiatively assisted vibronic de-excitation due to electromagnetic vacuum fluctuations on non-adiabatic processes. Building on our previous work [Tsai et al., J.
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