Articles tagged with "quantum-physics"
Quantum 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