This paper describes the so-called 1/f noise generated within the depleted region below a free semiconducting surface. It was shown that there is a link between the 1/f noise, which can be controlled by the band-bending, and the very narrow energy states (E<<kT) located on the top surface and vanishing into the bulk region. Also, it was shown that the noise can be lowered when the band-bending is reduced. A quantitative description of this reduction was provided. This study considered the n-type semiconductor.
We investigated low-frequency current fluctuations, i.e. noise, in the quasi-two-dimensional (2D) van der Waals antiferromagnetic semiconductor FePS3 with the electronic bandgap of 1.5 eV. The electrical and noise characteristics of the p-type, highly resistive, thin films of FePS3 were measured at different temperatures. The noise spectral density was of the 1/f - type over most of the examined temperature range but revealed well-defined Lorentzian bulges, and increased strongly near the Neel temperature of 118 K (f is the frequency). Intriguingly, the noise spectral density attained its mini…
Rare Transition Events in Nonequilibrium Systems with State-Dependent Noise: Application to Stochastic Current Switching in Semiconductor Superlattices
The ab-initio theory of low-field electronic transport properties such as carrier mobility in semiconductors is well-established. However, an equivalent treatment of electronic fluctuations about a non-equilibrium steady state, which are readily probed experimentally, remains less explored. Here, we report a first-principles theory of electronic noise for warm electrons in semiconductors. In contrast with typical numerical methods used for electronic noise, no adjustable parameters are required in the present formalism, with the electronic band structure and scattering rates calculated from fi…
The quantum indeterminacy caused by non-commutativity of observables at different times sets a lower bound on the voltage noise power spectrum in any conducting material. This bound is calculated explicitly in the case of semiconductors with a conical energy-momentum dispersion of charge carriers. It possesses all characteristic properties of 1/f noise. Its momentum decomposition is found to be singular at zero particle momentum, a measurable consequence being a sharp peak in the noise magnitude at small charge carrier density. In application to monolayer graphene, this peak becomes M-shaped o…
The test masses in next-generation gravitational-wave interferometers may have a semiconductor substrate, most likely silicon. The stochastic motion of charge carriers within the semiconductor will cause random fluctuations in the material's index of refraction, introducing a noise source called Thermal Charge Carrier Refractive (TCCR) noise. TCCR noise was previously studied in 2020 by Bruns et al., using a Langevin force approach. Here we compute the power spectral density of TCCR noise by both using the Fluctuation-Dissipation theorem (FDT) and accounting for previously neglected effects of…
We study high order harmonics generation (HHG) in crystalline silicon and diamond subjected to near and mid-infrared laser pulses. We employ time-dependent density functional theory and solve the time-dependent Kohn-Sham equation in the single-cell geometry. We demonstrate that clear and clean HHG spectra can be generated with careful selection of the pulse duration. In addition, we simulate dephasing effects in a large silicon super-cell through displacement of atomic positions prepared by a molecular dynamics simulation. We compare our results with the previous calculations by Floss et al. […
We present systematic temperature-dependent resistance noise measurements on a series of ferromagnetic Ga$_{1-x}$Mn$_{x}$As epitaxial thin films covering a large parameter space in terms of the Mn content $x$ and other variations regarding sample fabrication. We infer that the electronic noise is dominated by switching processes related to impurities in the entire temperature range. While metallic compounds with $x>2$ % do not exhibit any significant change in the low-frequency resistance noise around the Curie temperature $T_\mathrm{C}$, we find indications for an electronic phase separation …
Despite the growing interest in topological materials, the difficulty of experimentally synthesizing and integrating them with other materials has been one of the main barriers restricting access to their unique properties. Recent advances in synthesizing metastable phases of crystalline materials can help to overcome this barrier and offer new platforms to experimentally study and manipulate band topology. Because III-V semiconductors have a wide range of functional material applications (including optoelectronic devices, light-emitting diodes, and highly efficient solar cells), and because B…
Optical beam-induced scattering mode of mid-IR laser microscopy: a method for defect investigation in near-surface and near-interface regions of bulk semiconductors
Nonlinear stochastic discrete drift-diffusion theory of charge fluctuations and domain relocation times in semiconductor superlattices
提出了一种随机离散漂移扩散模型来解释弱耦合、高杂质半导体超晶格中散粒噪声的影响。它们的电流-电压特性由多个稳定的多稳态分支组成，对应于显示由畴壁分隔的两个畴的电场分布。如果初始状态对应于稳定分支中间的电压，并且突然电压被切换，使得最终电压对应于下一个分支，则畴在一定延迟时间之后重新定位。当最终电压接近第一电流分支末端的电压时，散粒噪声使延迟时间的分布从高斯分布变为第一通过时间分布。这些结果与Rogozia { \it et al}（Phys. Rev. B { \bf 64}，041308（R）（2001））的实验定性一致。
Imaging the high-frequency charging dynamics of a single impurity in a semiconductor on the atomic scale
Utrecht University（乌得勒支大学）；Leiden University（莱顿大学）；Ludwig-Maximilians-Universität（慕尼黑路德维希-马克西米利安大学）；University of Iowa（爱荷华大学）；Donostia International Physics Center (DIPC)（圣塞巴斯蒂安国际物理中心）；Eindhoven University of Technology（埃因霍温理工大学）；Munich Center for Quantum Science and Technology (MCQST)（慕尼黑量子科学与技术中心）
Quantum Noise Spectroscopy of Nanoscale Charge Defects in Silicon Carbide at Room Temperature
School of Biomedical Engineering, Division of Life Sciences and Medicine, University of Science and Technology of China（中国科学技术大学生命科学与医学部生物医学工程学院）；Laboratory of Spin Magnetic Resonance, School of Physical Sciences, Anhui Province Key Laboratory of Scientific Instrument Development and Application, University of Science and Technology of China（中国科学技术大学物理学院自旋磁共振实验室、安徽省科学仪器开发与应用重点实验室）；Suzhou Institute for Advanced Research, University of Science and Technology of China（中国科学技术大学苏州高等研究院）；Hefei National Laboratory, University of Science and Technology of China（中国科学技术大学合肥国家实验室）
Semiconductor nanowire field-effect transistors represent a promising platform for the development of room-temperature (RT) terahertz (THz) frequency light detectors due to the strong nonlinearity of their transfer characteristics and their remarkable combination of low noise-equivalent powers (< 1 nW/Hz$^{1/2}$) and high responsivities (> 100 V/W). Nano-engineering a NW photodetector combining high sensitivity with high speed (sub-ns) in the THz regime at RT is highly desirable for many frontier applications in quantum optics and nanophotonics, but this requires a clear understanding of the o…
