Spontaneous emission of an atom near a wedge

We re-examine the electrodynamic Casimir effect in a wedge defined by two perfect conductors making dihedral angle α = π/p. This system is analogous to the system defined by a cosmic string. We consider the wedge region as filled with an azimuthally symmetric material, with permittivity/permeability ε1, µ1 for distance from the axis r < a, and ε2, µ2 for r > a. The results are closely related to those for a circular-cylindrical geometry, but with non-integer azimuthal quantum number mp. Apart from a zero-mode divergence, which may be removed by choosing periodic boundary conditions on the wedge, and may be made finite if dispersion is included, we obtain finite results for the free energy corresponding to changes in a for the case when the speed of light is the same inside and outside the radius a, and for weak coupling, |ε1 − ε2| ≪ 1, for purely dielectric media. We also consider the radiation produced by the sudden appearance of an infinite cosmic string, situated along the cusp line of the pre-existing wedge.

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“…It is however simpler to go via the axial energy flux P , given as 14) where dA = rdrdθ is the cross-sectional area element, and where…”

Section: )mentioning

confidence: 99%

“…Local Casimir stresses were examined by Saharian and co-workers [10,11,12]. Rosa and collaborators studied the interaction of an atom with a wedge [13,14], the situation under which the closely related Casimir-Polder force was investigated by Sukenik et al some years ago [15]. That interaction was first worked out by Barton [16].…”

Section: Introductionmentioning

confidence: 99%

Electrodynamic Casimir effect in a medium-filled wedge

2009

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“…In [18] it was shown how the spontaneous emission rate is altered when placed inside a conducting wedge. Physically, this effect can be explained because the non-trivial boundary conditions affect the interaction between atoms and the quantum electromagnetic field.…”

Section: Discussionmentioning

confidence: 99%

“…At variance with these papers, we shall not consider the decaying of a superposition state but that of an excited one. On the other hand, the resemblances of our approach with the work in [17,18] (and references therein), where the authors have considered the modifications of the emission properties associated with the presence of boundaries, will be addressed in the Discussion section.…”

Section: Introductionmentioning

confidence: 99%

Entanglement of unstable atoms: modifications of the emission properties

Sancho

Plaja

2009

J. Phys. B: At. Mol. Opt. Phys.

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We analyse the influence of entanglement on the emission properties of atoms. To this end, first, we propose a scheme for the preparation of a pair of entangled Helium atoms, one in the ortho and the other in the para spin configuration. We discuss a realistic scenario for this process, based in the double ionization of He by intense laser fields. These states are used to analyse disentanglement and the role of entanglement in the spontaneous emission from the pair. In particular, we show that the decaying rate of an entangled atom is different from that in a product state, modifying the temporal emission distribution and lifetime of the atoms.

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“…To achieve such objective, several approaches have been proposed so far. One of them is to investigate SE in different system geometries [2][3][4][5][6][7][8][9][10][11] . Advances in nanofabrication techniques have not only allowed the increase of the spectroscopic resolution of molecules in complex environments 12 , but have also led to the use of nanometric objects, such as antennas and tips, to modify the lifetime, and enhance the fluorescence of single molecules [13][14][15][16] .…”

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confidence: 99%

Active magneto-optical control of spontaneous emission in graphene

et al. 2015

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We investigate the spontaneous emission rate of a two-level quantum emitter near a graphene-coated substrate under the influence of an external magnetic field or strain induced pseudo-magnetic field. We demonstrate that the application of the magnetic field can substantially increase or decrease the decay rate. We show that a suppression as large as 99% in the Purcell factor is achieved even for moderate magnetic fields. The emitter's lifetime is a discontinuous function of |B|, which is a direct consequence of the occurrence of discrete Landau levels in graphene. We demonstrate that, in the near-field regime, the magnetic field enables an unprecedented control of the decay pathways into which the photon/polariton can be emitted. Our findings strongly suggest that a magnetic field could act as an efficient agent for on-demand, active control of light-matter interactions in graphene at the quantum level.The possibility of tailoring light-matter interactions at a quantum level has been a sought-after goal in optics since the pioneer work of Purcell 1 , where it was first shown that the environment can strongly modify the spontaneous emission (SE) rate of a quantum emitter. To achieve such objective, several approaches have been proposed so far. One of them is to investigate SE in different system geometries [2][3][4][5][6][7][8][9][10][11] . Advances in nanofabrication techniques have not only allowed the increase of the spectroscopic resolution of molecules in complex environments 12 , but have also led to the use of nanometric objects, such as antennas and tips, to modify the lifetime, and enhance the fluorescence of single molecules [13][14][15][16] . The presence of metamaterials may also strongly affect quantum emitters' radiative processes. For instance, the impact of negative refraction and of the hyperbolic dispersion on the SE have been investigated [17][18][19] . Also, the influence of cloaking devices on the SE of atoms has been recently addressed 20 .Progress in plasmonics has also allowed for a unprecedented control of light-matter interactions at a quantum level. When the emitter is located near a plasmonic structure it may experience a strong enhancement of the local field. This effect can be exploited in the development of important applications in nanoplasmonics [21][22][23][24][25] . However, structures made of noble metals are hardly tunable, which unavoidably limit their application in photonic devices. To circumvent these limitations, graphene has emerged as an alternative plasmonic material due to its extraordinary electronic and optical properties [26][27][28][29][30][31] . Indeed, graphene hosts extremely confined plasmons, facilitating strong light-matter interactions [28][29][30][31] . In addition, the plasmon spectrum in doped graphene is highly tunable through electrical or chemical modification of the charge carrier density. Due to these properties, graphene is a promising material platform for several photonic applications, specially in the THz frequency range 30 . At the quantum leve...

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Spontaneous emission of an atom near a wedge

Cited by 19 publications

References 23 publications

Electrodynamic Casimir effect in a medium-filled wedge

Electrodynamic Casimir effect in a medium-filled wedge

Entanglement of unstable atoms: modifications of the emission properties

Active magneto-optical control of spontaneous emission in graphene

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