Chao Xiong

Higher-order nonclassical effects generated by multiple-photon annihilation-then-creation and creation-then-annihilation coherent states*

We explore two observable nonclassical properties of quantum states generated by repeatedly operating annihilation-then-creation (AC) and creation-then-annihilation (CA) on the coherent state, respectively, such as higher-order sub-Poissonian statistics and higher-order squeezing-enhanced effect. The corresponding analytical expressions are derived in detail depending on m. By numerically comparing those quantum properties, it is found that these states above have very different nonclassical properties and nonclassicality is exhibited more strongly after AC operation than after CA operation.

Ratchet Effect in a Triple Delta-Kicked Model

We investigate the quantum ratchet effect in a triple delta-kicked model. Three symmetric flashing potentials alternately act on a particle with a symmetric and homogeneous initial state of zero momentum. Ratchet currents emerge when quantum resonances are excited. Ratchet currents in the triple model may be stronger than those in the previous model. Our work expands upon the quantum delta-kicked model and may contribute to experimental investigation of the quantum transport of cold atoms.

Fabrication and Characterization of p-CuSCN/n-Si Heterojunction Diode

The p-CuSCN /n-Si heterojunction diode have been prepared at a low cost by chemical method. The prepared hexagonal β-CuSCN films are polycrystalline nature. The heterojunction shows a good rectifying behavior and photovoltaic effects. The current and 1/C2 versus voltage curve of the p-CuSCN/ n-Si heterojunction diode was shown. The linear relationships of 1/C2 versus voltage curve imply that the built-in potential Vbi and the conduction band offset of the heterojunction ware found to be 2.1 eV and 1.5 eV, respectively. The current transport mechanism is dominated by the space-charge limited current (SCLC) conduction at forward bias voltages. The electronic potential barrier in p-CuSCN/n-Si heterojunction interface higher than hole at forward bias voltages. In this voltages area, a single carrier injuction was induced and the main current of p-CuSCN/n-Si heterojunction is hole current.This heterojunction diode can be good used for light emission devices and photovoltaic devices.