半导体量子结构中之微波段电子传输特性之探测-HMLT低温高磁实验室.PDF

量 度 量 度 量 奈 來度 力 度 量 量 利 度 度 數 奈 了度度 兩金 狀 利靈 度量 率領靈 度 數 數 數 率 度量 量 兩 領 度 量量 C011 Probing the Microwave magnetotransport properties of Electrons in Semiconductor Quantum Structures The major contains of this one-year experimental proposal are: (1) to study the microwave magnetotransport properties of semiconductor quantum structures; (2) to study the effect on mesoscopic electron systems in the presence of microwave irradiations; (3) to study the electronic fluctuations, i.e. noises, in low-dimensional electron systems (LDESs). This project is our continuing endeavor to integrate microwave technique, cryogenic technique, and nano-lithography technique to study the transport properties of LDESs in semiconductors. The LDESs that we are interested are the following : (1) as-grown DLESs, such as simple 2DESs, self-assembled quantum wires and quantum dots; (2) electron-beam patterned DLESs with critical dimension below few hundred nm, usually fabricated from semiconductor heterostructures containing 2DESs. To study the magnetotransport properties of LDESs at microwave frequencies, we will either imbed the LDES in the gap of a 50Ω meandering coplanar waveguide (CPW), or arrange the LDES on the surface acoustic wave (SAW) delay line between two inter-digit transducers (IDTs). We will use the very unique ultra high-sensitivity vector microwave detection system based on phase-lock-loop (PLL) technique that we have developed to carefully scrutinize the change of the propagation properties of the samples while sweeping magnetic field with extremely low probing microwave power. We then extract the transport coefficients or electric polarization from the above data. The spectrum may also