Fluctuating electromagnetic fields and electron coherence

The coupling of the quantized electromagnetic field to coherent electrons is investigated. The effects both of photon emission and of the electromagnetic vacuum fluctuations upon electron interference are analyzed. The modifications of the vacuum fluctuations due to a conducting plate lead to a decrease in the amplitude of the interference oscillations. The possibility of observing this effect is discussed. It is also shown that there is an analogue of the Aharonov-Bohm effect in which electron interference is sensitive to vacuum fluctuations in regions from which the electrons are excluded.The coupling of the quantized electromagnetic field to coherent electrons is investigated. The effects both of photon emission and of the electromagnetic vacuum fluctuations upon electron interference are analyzed. The modifications of the vacuum fluctuations due to a conducting plate lead to a decrease in the amplitude of the interference oscillations. The possibility of observing this effect is discussed. It is also shown that there is an analogue of the Aharonov-Bohm effect in which electron interference is sensitive to vacuum fluctuations in regions from which the electrons are excluded.

Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fieldsJun 15, 199363 citations

Coherence in Electromagnetic Radiation

Physics TodayMay 1, 19600 citations

Decoherence of electron beams by electromagnetic field fluctuations

Yehoshua B. Levinson

Electromagnetic field fluctuations are responsible for the destruction of electron coherence (dephasing) in solids and in vacuum electron beam interference. The vacuum fluctuations are modified by conductors and dielectrics, as in the Casimir effect, and hence, bodies in the vicinity of the beams can influence the beam coherence. We calculate the quenching of interference of two beams moving in vacuum parallel to a thick plate with permittivity $\\epsilon(\\omega)=\\epsilon_{0}+i 4\\pi\\sigma/\\omega$ . In case of an ideal conductor or dielectric $(|\\epsilon|=\\infty)$ the dephasing is suppressed when the beams are close to the surface of the plate, because the random tangential electric field $E_{t}$ , responsible for dephasing, is zero at the surface. The situation is changed dramatically when $\\epsilon_{0}$ or $\\sigma$ are finite. In this case there exists a layer near the surface, where the fluctuations of $E_{t}$ are strong due to evanescent near fields. The thickness of this near - field layer is of the order of the wavelength in the dielectric or the skin depth in the conductor, corresponding to a frequency which is the inverse electron time of flight from the emitter to the detector. When the beams are within this layer their dephasing is enhanced and for slow enough electrons can be even stronger than far from the surface.Electromagnetic field fluctuations are responsible for the destruction of electron coherence (dephasing) in solids and in vacuum electron beam interference. The vacuum fluctuations are modified by conductors and dielectrics, as in the Casimir effect, and hence, bodies in the vicinity of the beams can influence the beam coherence. We calculate the quenching of interference of two beams moving in vacuum parallel to a thick plate with permittivity $\\epsilon(\\omega)=\\epsilon_{0}+i 4\\pi\\sigma/\\omega$. In case of an ideal conductor or dielectric $(|\\epsilon|=\\infty)$ the dephasing is suppressed when the beams are close to the surface of the plate, because the random tangential electric field $E_{t}$, responsible for dephasing, is zero at the surface. The situation is changed dramatically when $\\epsilon_{0}$ or $\\sigma$ are finite. In this case there exists a layer near the surface, where the fluctuations of $E_{t}$ are strong due to evanescent near fields. The thickness of this near - field layer is of the order of the wavelength in the dielectric or the skin depth in the conductor, corresponding to a frequency which is the inverse electron time of flight from the emitter to the detector. When the beams are within this layer their dephasing is enhanced and for slow enough electrons can be even stronger than far from the surface.

SPIE eBooksJun 1, 20040 citations

Decoherence of electron beams by electromagnetic field fluctuations

Yehoshua Levinson

Electromagnetic field fluctuations are responsible for the destruction of electron coherence (dephasing) in solids and in vacuum electron beam interference. The vacuum fluctuations are modified by conductors and dielectrics, as in the Casimir effect, and hence, bodies in the vicinity of the beams can influence the beam coherence. We calculate the quenching of interference of two beams moving in vacuum parallel to a thick plate with permittivity (ω) = 0 + i4πσ/ω. In the case of an ideal conductor or dielectric (| | = ∞) the dephasing is suppressed when the beams are close to the surface of the plate, because the random tangential electric field E t , responsible for dephasing, is zero at the surface. The situation is changed dramatically when 0 or σ is finite. In this case there exists a layer near the surface, where the fluctuations of E t are strong due to evanescent near fields. The thickness of this near-field layer is of the order of the wavelength in the dielectric or the skin depth in the conductor, corresponding to a frequency which is the inverse electron time of flight from the emitter to the detector. When the beams are within this layer their dephasing is enhanced and slow enough electrons can be even stronger than far from the surface.Electromagnetic field fluctuations are responsible for the destruction of electron coherence (dephasing) in solids and in vacuum electron beam interference. The vacuum fluctuations are modified by conductors and dielectrics, as in the Casimir effect, and hence, bodies in the vicinity of the beams can influence the beam coherence. We calculate the quenching of interference of two beams moving in vacuum parallel to a thick plate with permittivity (ω) = 0 + i4πσ/ω. In the case of an ideal conductor or dielectric (| | = ∞) the dephasing is suppressed when the beams are close to the surface of the plate, because the random tangential electric field E t , responsible for dephasing, is zero at the surface. The situation is changed dramatically when 0 or σ is finite. In this case there exists a layer near the surface, where the fluctuations of E t are strong due to evanescent near fields. The thickness of this near-field layer is of the order of the wavelength in the dielectric or the skin depth in the conductor, corresponding to a frequency which is the inverse electron time of flight from the emitter to the detector. When the beams are within this layer their dephasing is enhanced and slow enough electrons can be even stronger than far from the surface.

arXiv:quant-ph/0312184Journal of Physics A Mathematical and GeneralFeb 11, 200419 citations

Coherence Properties of the Electromagnetic Field

Daniel F. Walls, Gerard J Milburn

Springer eBooksDec 6, 20073 citations

\\epsilon(\\omega)=\\epsilon_{0}+i 4\\pi\\sigma/\\omega

. In case of an ideal conductor or dielectric

(|\\epsilon|=\\infty)

the dephasing is suppressed when the beams are close to the surface of the plate, because the random tangential electric field

E_{t}

, responsible for dephasing, is zero at the surface. The situation is changed dramatically when

\\epsilon_{0}

\\sigma

are finite. In this case there exists a layer near the surface, where the fluctuations of

E_{t}

are strong due to evanescent near fields. The thickness of this near - field layer is of the order of the wavelength in the dielectric or the skin depth in the conductor, corresponding to a frequency which is the inverse electron time of flight from the emitter to the detector. When the beams are within this layer their dephasing is enhanced and for slow enough electrons can be even stronger than far from the surface.