How does the quantum-to-classical transition of measurement occur?This question is vital for both foundations and applications of quantum mechanics.Here,we develop a new measurement-based framework for characterizing ...How does the quantum-to-classical transition of measurement occur?This question is vital for both foundations and applications of quantum mechanics.Here,we develop a new measurement-based framework for characterizing the classical and quantum free electron-photon interactions and then experimentally test it.We first analyze the transition from projective to weak measurement in generic light-matter interactions and show that any classical electron-laserbeam interaction can be represented as an outcome of weak measurement.In particular,the appearance of classical point-particle acceleration is an example of an amplified weak value resulting from weak measurement.A universal factor,exp(-Γ^(2)=2),quantifies the measurement regimes and their transition from quantum to classical,whereΓcorresponds to the ratio between the electron wavepacket size and the optical wavelength.This measurement-based formulation is experimentally verified in both limits of photon-induced near-field electron microscopy and the classical acceleration regime using a DLA.Our results shed new light on the transition from quantum to classical electrodynamics,enabling us to employ the essence of the wave-particle duality of both light and electrons in quantum measurement for exploring and applying many quantum and classical light-matter interactions.展开更多
Red-green-blue(RGB)full-color micro light-emitting diodes(μ-LEDs)fabricated from semipolar(20-21)wafers,with a quantum-dot photoresist color-conversion layer,were demonstrated.The semipolar(20-21)In Ga N/Ga Nμ-LEDs ...Red-green-blue(RGB)full-color micro light-emitting diodes(μ-LEDs)fabricated from semipolar(20-21)wafers,with a quantum-dot photoresist color-conversion layer,were demonstrated.The semipolar(20-21)In Ga N/Ga Nμ-LEDs were fabricated on large(4 in.)patterned sapphire substrates by orientation-controlled epitaxy.The semipolarμ-LEDs showed a 3.2 nm peak wavelength shift and a 14.7%efficiency droop under 200 A∕cm2injected current density,indicating significant amelioration of the quantum-confined Stark effect.Because of the semipolarμ-LEDs’emission-wavelength stability,the RGB pixel showed little color shift with current density and achieved a wide color gamut(114.4%NTSC space and 85.4%Rec.2020).展开更多
基金We thank Eilon Poem for helpful discussions,and we also thank Zhaopin Chen and Qingqing Cheng for their help in improving the figures.The work was supported in part by the Israel Innovation Authority Grants No.70002 and 73795,FQXi Grant No.224321Pazy Foundation,Israeli Ministry of Science and Technology,Canada Research Chair and Ontario’s Early Researcher Award,DIP(German-Israeli Project Cooperation),ISF(Israel Science Foundation)Grant No.00010001000,I-CORE-Israel Center of Research Excellence program of the ISFby the Crown Photonics Center,Gordon,and Betty Moore Foundation grant 4744(ACHIP),and ERC Advanced Grant 884217(AccelOnChip).
文摘How does the quantum-to-classical transition of measurement occur?This question is vital for both foundations and applications of quantum mechanics.Here,we develop a new measurement-based framework for characterizing the classical and quantum free electron-photon interactions and then experimentally test it.We first analyze the transition from projective to weak measurement in generic light-matter interactions and show that any classical electron-laserbeam interaction can be represented as an outcome of weak measurement.In particular,the appearance of classical point-particle acceleration is an example of an amplified weak value resulting from weak measurement.A universal factor,exp(-Γ^(2)=2),quantifies the measurement regimes and their transition from quantum to classical,whereΓcorresponds to the ratio between the electron wavepacket size and the optical wavelength.This measurement-based formulation is experimentally verified in both limits of photon-induced near-field electron microscopy and the classical acceleration regime using a DLA.Our results shed new light on the transition from quantum to classical electrodynamics,enabling us to employ the essence of the wave-particle duality of both light and electrons in quantum measurement for exploring and applying many quantum and classical light-matter interactions.
基金Ministry of Science and Technology,Taiwan,China(107-2221-E-009-113-MY3,108-2221-E-009-113-MY3)National Natural Science Foundation of China(11904302)+1 种基金Hsinchu Science Park Bureau,Ministry of Science and Technology,Taiwan,China(108A08B)Major Science and Technology Project of Xiamen,China(3502Z20191015)。
文摘Red-green-blue(RGB)full-color micro light-emitting diodes(μ-LEDs)fabricated from semipolar(20-21)wafers,with a quantum-dot photoresist color-conversion layer,were demonstrated.The semipolar(20-21)In Ga N/Ga Nμ-LEDs were fabricated on large(4 in.)patterned sapphire substrates by orientation-controlled epitaxy.The semipolarμ-LEDs showed a 3.2 nm peak wavelength shift and a 14.7%efficiency droop under 200 A∕cm2injected current density,indicating significant amelioration of the quantum-confined Stark effect.Because of the semipolarμ-LEDs’emission-wavelength stability,the RGB pixel showed little color shift with current density and achieved a wide color gamut(114.4%NTSC space and 85.4%Rec.2020).
