We report on an experiment with polarized atoms passing a standing light wave, where the atom's position is encoded (entangled) with the excitation amplitude of two long lived electronic states. Position information can be obtained a posteriori by measuring the electronic state. If this measurement is performed, the atom is localized in an array of virtual slits. This gives rise to diffraction of the atomic de Broglie waves from a measurement induced amplitude grating, thus showing the back action onto the momentum due to the localization. We further demonstrate experimentally that the encoding can be totally erased.We report on an experiment with polarized atoms passing a standing light wave, where the atom's position is encoded (entangled) with the excitation amplitude of two long lived electronic states. Position information can be obtained a posteriori by measuring the electronic state. If this measurement is performed, the atom is localized in an array of virtual slits. This gives rise to diffraction of the atomic de Broglie waves from a measurement induced amplitude grating, thus showing the back action onto the momentum due to the localization. We further demonstrate experimentally that the encoding can be totally erased.

Physical Review LettersMar 17, 1997120 citations

High-resolution amplitude and phase gratings in atom optics

P. R. Berman, B. Dubetsky, J. L. Cohen

An atom-field geometry is chosen in which an atomic beam traverses a field interaction zone consisting of three fields, one having frequency $\ensuremath{\Omega}=2\ensuremath{\pi}c/\ensuremath{\lambda}$ propagating in the $\mathbf{z\ifmmode \hat{}\else \^{}\fi{}}$ direction and the other two having frequencies $\ensuremath{\Omega}+{\ensuremath{\delta}}_{1}$ and $\ensuremath{\Omega}+{\ensuremath{\delta}}_{2}$ propagating in the $\ensuremath{-}\mathbf{z\ifmmode \hat{}\else \^{}\fi{}}$ direction. For ${n}_{1}{\ensuremath{\delta}}_{1}{+n}_{2}{\ensuremath{\delta}}_{2}=0$ and $|{\ensuremath{\delta}}_{1}|T,|{\ensuremath{\delta}}_{2}|T\ensuremath{\gg}1,$ where ${n}_{1}$ and ${n}_{2}$ are positive integers and T is the pulse duration in the atomic rest frame, the atom-field interaction results in the creation of atom amplitude and phase gratings having period $\ensuremath{\lambda}/[{2(n}_{1}{+n}_{2})].$ In this manner, one can use optical fields having wavelength \ensuremath{\lambda} to produce atom gratings having periodicity much less than \ensuremath{\lambda}.An atom-field geometry is chosen in which an atomic beam traverses a field interaction zone consisting of three fields, one having frequency $\ensuremath{\Omega}=2\ensuremath{\pi}c/\ensuremath{\lambda}$ propagating in the $\mathbf{z\ifmmode \hat{}\else \^{}\fi{}}$ direction and the other two having frequencies $\ensuremath{\Omega}+{\ensuremath{\delta}}_{1}$ and $\ensuremath{\Omega}+{\ensuremath{\delta}}_{2}$ propagating in the $\ensuremath{-}\mathbf{z\ifmmode \hat{}\else \^{}\fi{}}$ direction. For ${n}_{1}{\ensuremath{\delta}}_{1}{+n}_{2}{\ensuremath{\delta}}_{2}=0$ and $|{\ensuremath{\delta}}_{1}|T,|{\ensuremath{\delta}}_{2}|T\ensuremath{\gg}1,$ where ${n}_{1}$ and ${n}_{2}$ are positive integers and T is the pulse duration in the atomic rest frame, the atom-field interaction results in the creation of atom amplitude and phase gratings having period $\ensuremath{\lambda}/[{2(n}_{1}{+n}_{2})].$ In this manner, one can use optical fields having wavelength \ensuremath{\lambda} to produce atom gratings having periodicity much less than \ensuremath{\lambda}.

arXiv:physics/9806019Physical Review ADec 1, 199822 citations

Atomic diffraction by light gratings with very short wavelengths

Pedro Sancho

arXiv:1306.5458The European Physical Journal DJun 1, 20130 citations

Nearly-Resonant Gain Grating in Atomic Media

董雅宾 Dong Yabin, 庞嘉璐 Pang Jialu, 杨丽 YANG Li +1 more

Chinese Journal of LasersJan 1, 20212 citations

Asymmetric diffraction by atomic gratings with optical PT symmetry in the Raman-Nath regime

Tao Shui, Wen‐Xing Yang, Shaopeng Liu +2 more

We propose and analyze an efficient scheme for the lopsided Raman-Nath diffraction of one-dimensional ( $1\mathrm{D}$ ) and two-dimensional ( $2\mathrm{D}$ ) atomic gratings with periodic parity-time ( $\mathcal{PT}$ )-symmetric refractive index. The atomic grating is constructed by the cold-atomic vapor with two isotopes of rubidium, which is driven by weak probe field and space-dependent control field. Using experimentally achievable parameters, we identify the conditions under which $\mathcal{PT}$ -symmetric refractive index allows us to observe the lopsided Raman-Nath diffraction phenomenon and improve the diffraction efficiencies beyond what is achievable in a conventional atomic grating. The nontrivial atomic grating is a superposition of an amplitude grating and a phase grating. It is found that the lopsided Raman-Nath diffraction at the exceptional point (EP) of $\mathcal{PT}$ -symmetric grating originates from constructive and destructive interferences between the amplitude and phase gratings. Furthermore, we show that the $\mathcal{PT}$ -phase transition from unbroken to broken $\mathcal{PT}$ -symmetric regimes can modify the asymmetric distribution of the diffraction spectrum and that the diffraction efficiencies in the non-negative diffraction orders can be significantly enhanced when the atomic grating is pushed into a broken $\mathcal{PT}$ -symmetric phase. In addition, we also analyze the influence of the grating thickness on the diffraction spectrum. Our scheme may provide the possibility to design a gain-beam splitter with tunable splitting ratio and other optical components in integrated optics.We propose and analyze an efficient scheme for the lopsided Raman-Nath diffraction of one-dimensional ($1\mathrm{D}$) and two-dimensional ($2\mathrm{D}$) atomic gratings with periodic parity-time ($\mathcal{PT}$)-symmetric refractive index. The atomic grating is constructed by the cold-atomic vapor with two isotopes of rubidium, which is driven by weak probe field and space-dependent control field. Using experimentally achievable parameters, we identify the conditions under which $\mathcal{PT}$-symmetric refractive index allows us to observe the lopsided Raman-Nath diffraction phenomenon and improve the diffraction efficiencies beyond what is achievable in a conventional atomic grating. The nontrivial atomic grating is a superposition of an amplitude grating and a phase grating. It is found that the lopsided Raman-Nath diffraction at the exceptional point (EP) of $\mathcal{PT}$-symmetric grating originates from constructive and destructive interferences between the amplitude and phase gratings. Furthermore, we show that the $\mathcal{PT}$-phase transition from unbroken to broken $\mathcal{PT}$-symmetric regimes can modify the asymmetric distribution of the diffraction spectrum and that the diffraction efficiencies in the non-negative diffraction orders can be significantly enhanced when the atomic grating is pushed into a broken $\mathcal{PT}$-symmetric phase. In addition, we also analyze the influence of the grating thickness on the diffraction spectrum. Our scheme may provide the possibility to design a gain-beam splitter with tunable splitting ratio and other optical components in integrated optics.

Physical Review AMar 13, 201874 citations

{n}_{1}

and

{n}_{2}

are positive integers and T is the pulse duration in the atomic rest frame, the atom-field interaction results in the creation of atom amplitude and phase gratings having period $\ensuremath{\lambda}/[{2(n}_{1}{+n}_{2})].$ In this manner, one can use optical fields having wavelength \ensuremath{\lambda} to produce atom gratings having periodicity much less than \ensuremath{\lambda}.

We propose and analyze an efficient scheme for the lopsided Raman-Nath diffraction of one-dimensional (

1\mathrm{D}

) and two-dimensional (

2\mathrm{D}

) atomic gratings with periodic parity-time (

\mathcal{PT}

)-symmetric refractive index. The atomic grating is constructed by the cold-atomic vapor with two isotopes of rubidium, which is driven by weak probe field and space-dependent control field. Using experimentally achievable parameters, we identify the conditions under which

\mathcal{PT}

-symmetric refractive index allows us to observe the lopsided Raman-Nath diffraction phenomenon and improve the diffraction efficiencies beyond what is achievable in a conventional atomic grating. The nontrivial atomic grating is a superposition of an amplitude grating and a phase grating. It is found that the lopsided Raman-Nath diffraction at the exceptional point (EP) of

\mathcal{PT}

-symmetric grating originates from constructive and destructive interferences between the amplitude and phase gratings. Furthermore, we show that the

\mathcal{PT}

-phase transition from unbroken to broken

\mathcal{PT}

-symmetric regimes can modify the asymmetric distribution of the diffraction spectrum and that the diffraction efficiencies in the non-negative diffraction orders can be significantly enhanced when the atomic grating is pushed into a broken

\mathcal{PT}

-symmetric phase. In addition, we also analyze the influence of the grating thickness on the diffraction spectrum. Our scheme may provide the possibility to design a gain-beam splitter with tunable splitting ratio and other optical components in integrated optics.