No abstract

No abstract

The electronic structure tailoring of GaAs nanowires through surface modification was investigated by first-principles calculations. The effect of different surface-passivation materials (H, F, Cl, Br, and I) on the electronic structure of the GaAs nanowires was studied. The results show that for different atoms, the tailoring of the electronic structure is mainly determined by their passivation ability. The surface modification tunes the bandgap and also the bandgap types. The electronic structure of the GaAs nanowires was determined by the surface states and the quantum-confinement effect jointly. The amplitude of the bandgap variation on the diameter is different for the GaAs nanowires modified with different materials. Surface modification offers a new way to tailor the bandgap of GaAs nanowires without changing their diameter or crystal structure.

Stochastic decoding is an excellent approach for Low-Density Parity-Check (LDPC) codes which are adopted in many communication standards, including 10GBASE-T, DVB-S2, WiMAX. In this paper, we first research some novel schemes of stochastic LDPC decoding, like Noise-Dependent Scaling (NDS), Edge Memories (EMs), Tracking forecast memories (TFMs) and majority-based tracking Forecast Memories (MTFMs). (7, 4) Hamming code and (2048, 1723) LDPC code from the IEEE 802.3an standard are used to simulate and analyze the advantages and disadvantages of these methods. Then, an early termination criterion is proposed as an efficient way to speed up the decoding procedure. Simulation results show that our method can decrease the computation complexity significantly with negligible performance loss.

No abstract