Physical Review A

Low-light-level four-wave mixing by quantum interference

Author(s): Chang-Kai Chiu, Yi-Hsin Chen, Yen-Chun Chen, Ite A. Yu, Ying-Cheng Chen, and Yong-Fan Chen

We observed electromagnetically induced transparency-based four-wave mixing (FWM) in the pulsed regime at low light levels. The FWM conversion efficiency of 3.8(9)% was observed in a four-level system of cold 87Rb atoms using a driving laser pulse with a peak intensity of ≈80 μW/cm2, corresponding t...

[Phys. Rev. A 89, 023839] Published Mon Feb 24, 2014

Characterizing high-n quasi-one-dimensional strontium Rydberg atoms

Author(s): M. Hiller, S. Yoshida, J. Burgdörfer, S. Ye, X. Zhang, and F. B. Dunning

The production of high-n, n∼300, quasi-one-dimensional (quasi-1D) strontium Rydberg atoms through two-photon excitation of selected extreme Stark states in the presence of a weak dc field is examined using a crossed laser-atom beam geometry. The dipolar polarization of the electron wave function in ...

[Phys. Rev. A 89, 023426] Published Fri Feb 21, 2014

Terahertz laser based on dipolaritons

Author(s): K. Kristinsson, O. Kyriienko, and I. A. Shelykh

We develop the microscopic theory of a terahertz (THz) laser based on the effects of resonant tunneling in a double quantum well heterostructure embedded in both optical and THz cavities. In the strong-coupling regime the system hosts dipolaritons, hybrid quasiparticles formed by the direct exciton,...

[Phys. Rev. A 89, 023836] Published Fri Feb 21, 2014

Creating a tunable spin squeezing via a time-dependent collective atom-photon coupling

Author(s): Lixian Yu, Jingtao Fan, Shiqun Zhu, Gang Chen, Suotang Jia, and Franco Nori

We present an experimentally feasible method to produce a large and tunable spin squeezing when an ensemble of many four-level atoms interacts simultaneously with a single-mode photon and classical driving lasers. Our approach is to simply introduce a time-dependent collective atom-photon coupling. ...

[Phys. Rev. A 89, 023838] Published Fri Feb 21, 2014

Einstein-Podolsky-Rosen paradox and quantum steering in a three-mode optomechanical system

Author(s): Qiongyi He and Zbigniew Ficek

We study multipartite entanglement, the generation of Einstein-Podolsky-Rosen (EPR) states, and quantum steering in a three-mode optomechanical system composed of an atomic ensemble located inside a single-mode cavity with a movable mirror. The cavity mode is driven by a short laser pulse, has a non...

[Phys. Rev. A 89, 022332] Published Thu Feb 20, 2014

Quantum-path control and isolated-attosecond-pulse generation using H2+ molecules with moving nuclei in few-cycle laser pulses

Author(s): Xin-Lei Ge, Tian Wang, Jing Guo, and Xue-Shen Liu

We theoretically investigate the high-order harmonic generation (HHG) and isolated-attosecond-pulse generation from a full one-dimensional (1D) model of H2+ molecule in 3-fs, 800-nm laser pulses by using numerical solutions of the non-Born-Oppenheimer time-dependent Schrödinger equation (TDSE). The ...

[Phys. Rev. A 89, 023424] Published Thu Feb 20, 2014

Sub-Doppler resonances in the backscattered light from random porous media infused with Rb vapor

Author(s): S. Villalba, A. Laliotis, L. Lenci, D. Bloch, A. Lezama, and H. Failache

We report on the observation of sub-Doppler resonances on the backscattered light from a random porous glass medium with rubidium vapor filling its interstices. The sub-Doppler spectral lines are the consequence of saturated absorption where the incident laser beam saturates the atomic medium and th...

[Phys. Rev. A 89, 023422] Published Wed Feb 19, 2014

Extremely asymmetric electron localization in H2+ controlled with a THz field

Author(s): Zhengmao Jia, Zhinan Zeng, Ruxin Li, Zhizhan Xu, and Yunpei Deng

We propose a scheme to achieve extremely asymmetric electron localization during molecular dissociations. Hydrogen molecular ion (H2+) dissociation is investigated theoretically. A THz pulse is used to steer the electron motion after the molecular ion is excited by an ultrashort ultraviolet laser pu...

[Phys. Rev. A 89, 023419] Published Tue Feb 18, 2014

Disclosing intrinsic molecular dynamics on the 1-fs scale through extreme-ultraviolet pump-probe measurements

Author(s): P. A. Carpeggiani, P. Tzallas, A. Palacios, D. Gray, F. Martín, and D. Charalambidis

Through frequency up-conversion of polarization-shaped, femtosecond laser pulses nonlinearly interacting with xenon atoms, energetic, broadband, coherent, XUV continuum radiation is generated. By exploiting the thus-formed short-duration XUV pulses, all the optically allowed excited states of H2 are...

[Phys. Rev. A 89, 023420] Published Tue Feb 18, 2014

Similarity properties in the dynamics of delayed-feedback semiconductor lasers

Author(s): Xavier Porte, Miguel C. Soriano, and Ingo Fischer

Semiconductor lasers with delayed feedback exhibit two fundamentally different dynamical states: weak and strong chaos. We characterize experimentally the mechanism for the emergence of strong chaos. Based on these insights, we demonstrate similarity properties for long delays, i.e., similar dynamic...

[Phys. Rev. A 89, 023822] Published Tue Feb 18, 2014

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