New Type of Nonlinear Optical Device using Charge-Density-Wave Collective Motion

利用电荷密度波集体运动的新型非线性光学器件

基本信息

批准号：
12650039
负责人：
KOYANO Mikio
金额：
$ 1.92万
依托单位：
Japan Advanced institute of Science and Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

项目摘要

(i) Charge density fluctuation and density modulation in ideal 2-dimensional electron systemsResonant light scattering spectra from modulation doped n-type AlGaAs/GaAs single heterojunctions are studied experimentally and theoretically. Based on the light scattering formula due to the charge-density mechanism, the scattering intensities by coupled intersubband plasmon-LO phonon modes are analyzed by taking into account the electron-electron and electron-phonon interactions. Moreover, we carry out a self-consistent calculation of the density modulation of the 2-dimensional electron gas in a lateral surface superlattice.(ii) Charge-density-waves in transition-metal dichalcogenidesSingle crystals of quasi-two-dimensional conductor of TaS_2 have been synthesized by chemical vapor transport technique. Excess sulfur addition at the synthesis suppressed the charge-density-wave transition through a conduction carrier injection; the thermopower measurements revealed that the injected carrier is hole.(iii) Photo-irradiation effect on dynamics of charge-density-wave condensate in quasi-one-dimensional conductorsWe find a new photo-irradiation effect on the current-voltage characteristics of quasi-one-dimensional conductors TaS_3. When the TaS_3 single crystal is irradiated with a weak 488 nm emission from Ar^+ laser, the electrical current is enhanced around the threshold voltage V_t below the Peierls transition temperature T_p. The current enhancement is attributed to the increase of charge-density-wave contribution due to the screened pinning potentials by photo-excited quasi-particles in plastic creep phase of charge-density-wave motion.

（i）在实验和理论上研究了掺杂的N型N型藻类/GAAS单个异质结的理想二维电子系统的电荷波动和密度调制。根据电荷密度机制引起的光散射公式，通过考虑电子电子和电子 - phonon相互作用，分析了耦合的子带等离子-LO声子模式的散射强度。此外，我们对侧面表面超晶格中的二维电子气体的密度调节进行了自洽计算。（ii）TAS_2的Quasi-Two-Two-Two-dimensional导体的过渡金属二分法晶体中的电荷密度波已经通过化学VAPOR运输技术合成。合成时过量的硫添加通过传导载体注入抑制了电荷密度的转变。热电器测量结果表明，注入的载体是孔。（iii）光辐照对Quasi-One维电量中电荷密度波冷凝物动力学的效应，发现对准中二维导体电流特性的新光照射效应TAS_3。当Tas_3单晶被AR^+激光器发射弱的488 nm发射时，在PEIERLS过渡温度T_P以下的阈值电压v_t附近增强了电流。当前的增强归因于电荷密度波贡献的增加，因为在电荷密度波运动的塑性蠕变相中，通过光启用的准准粒子筛选了电势。