Gongwei Lin

Strong photon blockade with intracavity electromagnetically induced transparency in a blockaded Rydberg ensemble

We consider the dynamics of intracavity electromagnetically induced transparency (EIT) in an ensemble of strongly interacting Rydberg atoms. By combining the advantage of variable cavity lifetimes with intracavity EIT and strongly interacting Rydberg dark-state polaritons, we show that such intracavity EIT system could exhibit very strong photon blockade effect.

Quantum entangling gates using the strong coupling between two optical emitters and nanowire surface plasmons.

We propose a scheme to generate quantum entangling gate using one-dimensional surface plasmon waveguide. The protocol is based on the detection of the transmission spectrum of the single optical plasmons passing through two separate three-level emitters on metallic nanowire waveguide. It is shown that the low efficiency in direct detection of the single photon can be avoided by repeating the measurement of the transmission spectrum.

Guiding light by the modulated electromagnetically induced transparency

We propose a scheme for guiding light by the modulated electromagnetically induced transparency (EIT) in a three-level atomic system. By using a periodically modulated control field, the linear and nonlinear susceptibilities are changed cyclically for the probe field, which results in the deflection of propagation direction of the probe beam. Propagation direction/path and output position of the probe soliton in the modulated EIT medium can be controlled precisely via adjusting the modulation period of the control field. By changing its initial amplitude, the probe beam can also be guided to a desired output position in the atomic system, driven by a periodic control field. These properties offer a novel way of soliton control, based on the modulated EIT effect.

Cavity linewidth narrowing with dark-state polaritons

We present a quantum-theoretical treatment of cavity linewidth narrowing with intracavity electromagnetically induced transparency (EIT). By means of intracavity EIT, the photons in the cavity are in the form of cavity polaritons: bright-state polariton and dark-state polariton. Strong coupling of the bright-state polariton to the excited state induces an effect known as vacuum Rabi splitting, whereas the dark-state polariton decoupled from the excited state induces a narrow cavity transmission window. Our analysis would provide a quantum theory of linewidth narrowing with a quantum field pulse.

Strong mechanical squeezing in an electromechanical system

The mechanical squeezing can be used to explore quantum behavior in macroscopic system and realize precision measurement. Here we present a potentially practical method for generating strong squeezing of the mechanical oscillator in an electromechanical system. Through the Coulomb interaction between a charged mechanical oscillator and two fixed charged bodies, we engineer a quadratic electromechanical Hamiltonian for the vibration mode of mechanical oscillator. We show that the strong position squeezing would be obtained on the currently available experimental technologies.

Detuning-induced stimulated Raman adiabatic passage in dense two-level systems

Abstract We investigate the coherence generation in dense two-level systems under detuning-induced stimulated Raman adiabatic passage (D-STIRAP). In the dense two-level system, the near dipole–dipole (NDD) interaction should be taken into consideration. With the increase in the strength of the NDD interaction, it is found that a switchlike transition of the generated coherence from maximum value to zero appears. Meanwhile, the adiabatic condition of the D-STIRAP is destroyed in the presence of the NDD interaction. In order to avoid the sudden decrease in the generated coherence and maintain the maximum value, we can use stronger detuning pulse or pump pulse, between which increasing the intensity of the detuning pulse is of more efficiency. Except for taking advantage of such maximum coherence in the high density case into areas like enhancing the four-wave mixing process, we also point out that the phenomenon of the coherence transition can be applied as an optical switch.