Narrow Results

The possible existence of quantum crystals phase of polariton condensate in two-dimensional microcavity polariton was studied by using mean-field method for bosons at zero temperature. In this study, we observe the supersolid crystallized (hexagonal, square) and a quantized winding number of the phase in a regime of strong- field interaction in rotating exciton–polariton condensates. First, the ground state of the condensate was found; and the solution was further extended for dynamics state to reach the equilibrium steady-state as well as their density profile and energy diagrams. The supersolid crystal is the result of the considerable deviation induced by the interaction of polaritons of both ground and dynamic states of a dressed dipolar Bose–Einstein condensate. Here, the researchers demonstrated the formation of a hexagonal lattice in the nonlinear regime at high polariton-density where polariton–polariton interactions dominate the behavior of the system. It was identified that stability regimes for ground state increases as the polariton–polariton interaction strength increases. The phase diagram for the stable vortex state will be useful for conducting experimental and theoretical studies on rotating dipolar quantum gases and many other exotic systems.

The autocorrelation function of the light emitted by a microcavity containing a semiconductor quantum well in the nonstationary regime is investigated. An analytical expression in the weak pumping and strong coupling regime is derived. Furthermore, it is shown that the initial entangled state can be deduced from the nonstationary autocorrelation function.

We propose a scheme to carry out quantum phase gate in one step by bichromatic radiation method with semiconductor quantum dots (QDs) embedded in a single mode microcavity. The spin degrees of freedom of the only excess conduction band electron are employed as qubits and excitonic states are used as auxiliary states. The nearest-neighbor coupling is not required because the cavity mode plays the role of data bus. We show how to perform quantum computing with properly tailored laser pulses and Pauli-blocking effect, without exciting the cavity mode.

Starting with one-cavity side-coupled with waveguide system, we theoretically study on transmission spectrum for a two-cavity side-coupled with waveguide system based on coupled mode theory by using light-tracing method. Interesting effects called all-optical analog to EIT appear in some cases. 3D finite-difference time-domain (FDTD) method provides optical modes distributions at different wavelengths, including the EIT-like wavelength. Influences of different parameters on the narrow EIT-like peak such as cavity quality factors Q, frequency difference detuning Δω, and phase difference detuning between cavities ΔΦ are discussed. Compared with previous studies, this method is easier to understand and can be used as a model for both standing cavities like line-defect photonic crystal cavities and whispering gallery modes cavities like microring cavities.

A polymeric solid-state microcavity dye laser of the size comparable to a lasing wavelength is modeled by means of the finite element method (FEM). Lasing modes are calculated taking into account the gain material properties, such as absorption, dispersion and fluorescence. Study of the microcavity tolerance against possible geometrical imperfections demonstrates good robustness of the chosen shape and stability of the operation under possible cavity distortions.

Isolating circulating tumor cells (CTCs) from the blood plays an important role in the specific treatment of tumor diseases. In this study, a dissipative particle dynamics method combined with a spring-based cell model was employed to simulate the motion of a single or two cells in the microchannel with a square cavity. For a single cell with a small diameter, it will be captured by the square cavity at an appropriate flow rate. For cells whose diameter is not small enough compared to the opening size of the square cavity, they will not be captured at any flow rate. Based on this, cells of different sizes could be successfully separated when passing through this microchannel. Through the analysis of the flow behavior of uncaptured cells, the movement of cells in microchannels is divided into four stages: “guiding,” “rapid,” “slow”, and “ascending” according to the lateral movement speed and centroid position of cells. When the CTC moves together with a red blood cell, as the flow rate decreases, it would be trapped by the microcavity, whereas the RBC is not captured. Thus, CTC can be isolated from blood samples of cancer patients. The method of predicting cell movement behavior through simulation can also provide some reference for the design of microfluidic channels.

Experimental study of Resonant Rayleigh Scattering (RRS) of light by a semiconductor microcavity was carried out on a double cavity sample. The shifts of RRS lines spectral positions with sample rotation demonstrate clearly polariton dispersion. The shape of the lines depends strongly on the position of the excitation spot on the structure surface and temperature. The treatment of experimental data in terms of the Fano quantum mechanical interference between a discreet state and continuum gives a direct method to study polariton scattering probabilities.

The degeneracy of the two fundamental modes HE₁₁ of the nanowire (NW) is removed due to the coupling of surface plasmon (SP). For the coupled mode 1 of HE₁₁ the electric field is concentrated between the metal sphere and the NW because of the coupling of the metal sphere. The coupling intensity depends on the relative position of the metal sphere. There is no field concentration phenomenon for the coupled mode 2 of HE₁₁, and the coupling only affects the distribution of the local field in the NW. For the coupled mode 2 of HE₁₁, both the mode volume and the Purcell factor do not have obvious change. However, for the coupled mode 1 of HE₁₁ both the mode volume and the Purcell factor have a fundamental change. The mode volume increases with the increase of the metal sphere distance from the point of maximum field intensity of the Fabry–Perot standing wave. The Purcell factor decreases with the increase of the metal sphere distance from the point of maximum field intensity of the Fabry–Perot standing wave.