Ultrahigh-sensitivity far infrared photodetectors by using the quantum Hall effect

当两个尺寸电子系统（2DES）被提交给低温下的强磁场时，电子的运动完全量化了像环球运动和O尺寸一样，相等距离能量水平（Landaulevels）形成。在这样的情况下，一种新颖的现象被称为量子大厅效应。也可以说，量子霍尔效应（QHE）已被应用于抵抗标准的最常用，我们正在寻求使用QHE来检测远红外辐射（或有时称为Terahertz辐射）。这个项目的主要结果是：（1）我们发现了2DES的双重抗性展品，在量子霍尔州的受害者中有一个非常大的光敏感性。从激发特性的分析中，它明确了光敏感性是由cyclotron resonance absorption定义的，并且在这个过程中有两个机制。e.，（i）将电子加热到光吸收;（ii）将边缘信道传输通过空间分离的潜在再分配来调制光子激发电子和洞。（2） The responsivity of the QHE detector increases linearly with increasing the bias current and reaches 10-D17-D1V/W， which is 1000 times larger than that of conventional bolometers。进一步增加了在降低对焦耳加热的反应中的反应力，即进一步增加。（3）我们发现QHE探测器的主要噪音是1/f噪音，而且它很快就增加了偏差电流。同时，在相对较低的偏差电流（-μA）中获得了最大检测力。（4） The overall detectivity of the QHE photodetector was estimated to be 3 x10 y D113 y D1Hz y D11/2 y D1cm/W， which is approximately 50 times larger than that of conventional bolometers。这是一个高检测性指数，它是QHE光电探测器的优越性，是远红外光电探测器的超灵敏度。

When a two-dimensional electron system (2DES) is subjected to a strong magnetic field at low temperatures, the motion of electrons are completely quantized by cyclotron motion and O-dimensional like, equi-distant energy levels (Landau levels) are formed. In such a situation, a novel phenomenon called the quantum Hall effect appears. Although the quantum Hall effect (QHE) is most often applied to resistance standards, we are pursuing a possibility of using QHE for the detection of far infrared radiation (or sometimes called terahertz radiation). The major results of this project are ;(1) We have found that the diagonal resistance of the 2DES exhibits a very large photosensitivity in the vicinity of the quantum Hall states. From the analysis of the excitation spectra, it is clarified that the photosensitivity is induced by the cyclotron resonance absorption and that there are two mechanisms in the process, i. e., (i) electron heating due to photoabsorption and (ii) modulation of edge channel transport through potential redistribution by spatial separation of photoexcited electron and holes.(2) The responsivity of the QHE detector increases linearly with increasing the bias current and reaches 10ィイD17ィエD1 V/W, which is 1000 times larger than that of conventional bolometers. Further increase of the bias current results in the reduction in responsivity due to joule heating.(3) We have found that the dominant noise of the QHE detector is the 1/f noise and that it increases very quickly with increasing the bias current. Consequently, the maximum detectivity was obtained at relatively low bias currents (-μA).(4) The overall detectivity of the QHE photodetector was estimated to be 3x10ィイD113ィエD1 HzィイD11/2ィエD1cm/W, which is approximately 50 times larger than that of conventional bolometers. This high detectivity indicates the superiority of the QHE photodetector as a ultirahigh-sensitivity far infrared photodetector.