Entanglement between collective fields via phase-dependent electromagnetically induced transparency

Wang, Fei; Hu, Xiangming; Shi, Wenxing; Yu-Zhu, Zhu

doi:10.1103/physreva.81.033836

Cited by 33 publications

(18 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our work paves the way for the realization of such proposals, since inevitable laser frequency noise induces classical correlations in the same way as studied here [21], and understanding its behavior is necessary for achieving quantum correlations. Furthermore, the sharp transition from correlation to anticorrelation observed here has a close resemblance to the behavior of quantum correlations predicted in [22], and are both resulted from the coherence induced sharp dispersion.…”

supporting

confidence: 78%

Coherence-Assisted Resonance with Sub-Transit-Limited Linewidth

Feng

Jiang

et al. 2012

Phys. Rev. Lett.

View full text Add to dashboard Cite

We demonstrate a novel approach to obtain resonance linewidth below that limited by coherence lifetime. Cross correlation between induced intensity modulation of two lasers coupling the target resonance exhibits a narrow spectrum. 1/30 of the lifetime-limited width was achieved in a proof-ofprinciple experiment where two ground states are the target resonance levels. Attainable linewidth is only limited by laser shot noise in principle. Experimental results agree with an intuitive analytical model and numerical calculations qualitatively. This technique can be easily implemented and should be applicable to many atomic, molecular and solid state spin systems for spectroscopy, metrology and resonance based sensing and imaging.Achieving narrow resonance is of long lasting interest to both fundamental and applied sciences such as spectroscopy, precision measurement, metrology, and sensing. Resonance lines are often broadened, for example, by Doppler effects, inhomogeneous local fields, power broadening, etc. Techniques to reduce these effects include laser cooling and trapping of atoms, rephasing via pulse sequences and Ramsey type pump-probe method [1]. Nonetheless, resonance linewidth is ultimately limited by the lifetimes of involved atomic states, which determine the natural linewidth or more broadly the lifetime-limited linewidth. How to go beyond this limit has been a longstanding important challenge. Existing efforts can be grouped into two categories. In the first category, subnatural optical resonance is enabled by a much narrower resonance coupled to the target resonance [2][3][4]. There, the attainable linewidth cannot beat the natural width of the narrower resonance. In the second category, a time resolved pump-probe method in the same spirit of the Ramsey spectroscopy is used to detect the longer-lived subset of an atomic ensemble [5][6][7][8][9].We here report a new method which uses continuouswave (CW) lasers to obtain linewidth far below the coherence lifetime limit. Our technique utilizes coherence between the two lower states in a three-level system exhibiting electromagnetically induced transparency (EIT) [10] or coherent population trapping (CPT) [11]. The resonance of interest is between two lower states and the attainable linewidth is much narrower than the width set by the lifetime of the ground state coherence. The narrowing factor is only determined by the laser frequency modulation parameters, and is limited by technical noise and eventually laser shot noise. In a proof-of-principle experiment, we have observed 1/30 of the lifetime-limited width by employing frequency modulated CW lasers. Since this technique is easy to implement and only requires a Ra- man/CPT process which exists in many systems such as atoms, molecules, and solid state spins, we believe it will have broad applications.The principle of this technique is illustrated in Fig. 1. Two metastable ground states |1 and |2 are resonantly coupled to an auxiliary fast-decaying level |3 by two optical fields E 1 and E 2 under same fr...

show abstract

supporting

confidence: 78%

Coherence-Assisted Resonance with Sub-Transit-Limited Linewidth

Feng

Jiang

et al. 2012

Phys. Rev. Lett.

View full text Add to dashboard Cite

show abstract

“…We note that the sharp transition from correlation to anticorrelation here has an inherent connection with the predicted sudden appearance of entanglement between collective optical modes when Raman detuning deviates from zero [26]. In ref [26], a phase sensitive EIT based on a double Λ system is considered, where each Λ couples two optical fields, and the two fields coupling to the same ground state form a quantum beat and hence can be viewed as a collective field.…”

Section: Methodsmentioning

confidence: 74%

Transition linewidth of cross correlations in random intensity fluctuations in electromagnetically induced transparency

Feng

Zhang

et al. 2014

Phys. Rev. A

View full text Add to dashboard Cite

It is known that cross-correlation between the random intensity fluctuations of two lasers forming electromagnetically-induced transparency (EIT) exhibits a transition from correlation to anticorrelation. We study the linewidth behavior of this transition and have found the linewidth is below the (effective) coherence lifetime limit and is only limited by competing noises. We established a numerical model which reveals the linewidth dependence on laser linewidth and laser power. Our experiments using lasers with different linewidth showed results in qualitative agreement with the model. This result is useful for quantum optics using EIT, and may also have applications in spectroscopy and precision measurements.

show abstract

“…An additional control field with moderate strength drives transition |2 ↔ |4 with Rabi frequency Ω c . A similar system was widely used in quantum optical experiments, such as the giant Kerr effect [29][30][31], optical switch [32][33][34], four-wave mixing [35,36], collective field entanglement [37], and optical precursors [38,39], etc. The dynamics of the atomic system can be described using the density-matrix approach aṡ…”

Section: Model and Basic Equationsmentioning

confidence: 99%

Enhanced gain and narrow linewidth of an optical cavity by the Doppler effect in a four-level atomic system

Peng

Yang

Zhang

et al. 2013

Journal of Modern Optics

View full text Add to dashboard Cite

2013) Enhanced gain and narrow linewidth of an optical cavity by the Doppler effect in a four-level atomic system, Journal of Modern Optics, 60:13, Ascheme for high gain and narrow linewidth of an optical cavity with a four-level atomic system is proposed by the Doppler effect via active Raman gain (ARG) process. Atomic motion leads to Doppler frequency shift which induces constructive interference for the linear susceptibility. The enhanced normal dispersion greatly narrows the cavity linewidth, and the amplified gain gives rise to a high cavity transmission. Simulation results show that the cavity linewidth based on ARG is about one order of magnitude narrower than that based on electromagnetically-induced transparency under the same conditions, and the cavity transmission intensity could be enhanced by nearly 30 times.

show abstract

Entanglement between collective fields via phase-dependent electromagnetically induced transparency

Cited by 33 publications

References 58 publications

Coherence-Assisted Resonance with Sub-Transit-Limited Linewidth

Coherence-Assisted Resonance with Sub-Transit-Limited Linewidth

Transition linewidth of cross correlations in random intensity fluctuations in electromagnetically induced transparency

Enhanced gain and narrow linewidth of an optical cavity by the Doppler effect in a four-level atomic system

Contact Info

Product

Resources

About