Articles tagged with "quantum-physics"
Tiny quantum sensor breaks noise limits, could boost MRI, space tech
Researchers at the Niels Bohr Institute (NBI) at the University of Copenhagen have developed a novel tunable quantum sensing system that significantly improves measurement accuracy by overcoming noise limits inherent in conventional optical sensors. This tabletop device leverages large-scale entanglement by pairing a multi-photon light state with a large atomic spin ensemble, enabling frequency-dependent squeezing of light. This approach reduces quantum noise across a broad frequency range by dynamically adjusting the phase and amplitude of light, which traditional systems cannot achieve without large-scale infrastructure. The innovation addresses both back-action noise—disturbances caused by the measurement process—and detection noise, enhancing sensor sensitivity beyond the standard quantum limit. Unlike previous frequency-dependent squeezing applications that require extensive optical resonators (around 300 meters long), the NBI team’s compact system achieves similar performance on a tabletop scale. Potential applications include improved detection of time variations, acceleration, and magnetic fields, with significant implications for biomedical imaging such as enhancing MRI resolution for earlier neurological disorder diagnosis, as well
quantum-sensingoptical-sensorsquantum-noise-reductiontunable-quantum-systembiomedical-technologyspace-technologyquantum-physicsQuantum embezzlement is hiding in known one-dimensional materials: Study
A recent study by researchers at Leibniz University Hannover in Germany has demonstrated that the phenomenon of quantum embezzlement—previously thought to exist only in idealized, infinite quantum systems—can actually occur in real, finite one-dimensional materials known as critical fermion chains. Quantum embezzlement is a unique form of entanglement where one system can supply entanglement to another, enabling state changes without itself being altered, analogous to borrowing resources without depletion. The study found that these critical fermion chains, which are highly entangled systems at phase transition points, satisfy the strict criteria for universal embezzlement, meaning they can assist in creating any entangled state across various scenarios. Importantly, the researchers showed that this embezzlement property is not limited to infinite systems (the thermodynamic limit) but also emerges in large, finite fermion chains that could be experimentally realized. This suggests that quantum embezzlement is not merely a theoretical curiosity but a physical effect
quantum-materialsfermion-chainsquantum-entanglementquantum-information-transferquantum-physicsquantum-embezzlementmaterials-scienceQuantum tunneling time cracked: Electrons barely pause before escaping
A recent study has resolved the long-standing question of how long quantum tunneling takes by introducing a novel phase-resolved attoclock technique. Quantum tunneling, where electrons pass through energy barriers they normally couldn't cross, occurs on attosecond timescales, making direct measurement extremely challenging. Traditional attoclock methods, which use rotating elliptical laser fields to infer tunneling times from electron emission angles, have produced inconsistent results due to complex interpretations and distortions. The new approach employs perfectly circularly polarized laser light combined with precise control of the carrier-envelope phase (CEP), allowing researchers to track the exact peak of the electric field that triggers electron escape, thereby eliminating non-time-dependent distortions and improving measurement reliability. Using this refined method, the researchers found that electrons do not experience any measurable delay during tunneling; they essentially "barely pause" before escaping the atom. Instead, the key factor influencing electron emission is the strength of the atom’s hold on the electron prior to tunneling, not the tunneling duration itself. This finding challenges previous assumptions about tunneling dynamics and has significant implications for modeling ultrafast atomic and molecular processes. Additionally, the study suggests that the phase-resolved attoclock technique is stable and precise enough to be adapted for real-time chemical analysis, potentially advancing applications in ultrafast spectroscopy and quantum technologies.
materialsquantum-tunnelingattoclock-techniqueelectron-dynamicslaser-physicsquantum-physicsultrafast-measurementZEUS: US facility fires world’s most powerful laser at 2 petawatts
energylaser-technologymaterials-sciencequantum-physicsplasma-sciencescientific-discoveryhigh-field-science