The problem of quantum chaotic scattering with direct processes reduced to the one without

We show that the study of the statistical properties of the scattering matrix S for quantum chaotic scattering in the presence of direct processes (charaterized by a nonzero average S matrix ) can be reduced to the simpler case where direct processes are absent ( = 0). Our result is verified with a numerical simulation of the two-energy autocorrelation for two-dimensional S matrices. It is also used to extend Wigner's time delay distribution for one-dimensional S matrices, recently found for = 0, to the case not equal to zero; this extension is verified numerically. As a consequence of our result, future calculations can be restricted to the simpler case of no direct processes.Comment: 9 pages (Latex) and 1 EPS figure. Submitted to Europhysics Letters. The conjecture proposed in the previous version is proved; thus the present version contains a more satisfactory presentation of the proble

Non-analyticity in the distribution of conductances in quasi one dimensional wires

We show that the distribution P(g) of conductances g of a quasi one dimensional wire has non-analytic behavior in the insulating region, leading to a discontinuous derivative in the distribution near g=1. We give analytic expressions for the full distribution and extract an approximate scaling behavior valid for different strengths of disorder close to g=1.Comment: 7 pages, 3 figures. Submitted to Europhysics Letter

Controlling conductance statistics of quantum wires by driving ac fields

We calculate the entire distribution of the conductance P(G) of a one-dimensional disordered system --quantum wire-- subject to a time-dependent field. Our calculations are based on Floquet theory and a scaling approach to localization. Effects of the applied ac field on the conductance statistics can be strong and in some cases dramatic, as in the high-frequency regime where the conductance distribution shows a sharp cut-off. In this frequency regime, the conductance is written as a product of a frequency-dependent term and a field independent term, the latter containing the information on the disorder in the wire. We thus use the solution of the Mel'nikov equation for time-independent transport to calculate P(G) at any degree of disorder. At lower frequencies, it is found that the conductance distribution and the correlations of the transmission Floquet modes are described by a solution of the Dorokhov-Mello-Pereyra-Kumar equation with an effective number of channels. In the regime of strong localization, induced by the disorder or the ac field, P(G) is a log-normal distribution. Our theoretical results are verified numerically using a single-band Anderson Hamiltonian.Comment: 6 pages, 4 figures. V2: a new reference added. Minor correction

Statistical analysis of the transmission based on the DMPK equation: An application to Pb nano-contacts

The density of the transmission eigenvalues of Pb nano-contacts has been estimated recently in mechanically controllable break-junction experiments. Motivated by these experimental analyses, here we study the evolution of the density of the transmission eigenvalues with the disorder strength and the number of channels supported by the ballistic constriction of a quantum point contact in the framework of the Dorokhov-Mello-Pereyra-Kumar equation. We find that the transmission density evolves rapidly into the density in the diffusive metallic regime as the number of channels $N_c$ of the constriction increase. Therefore, the transmission density distribution for a few $N_c$ channels comes close to the known bimodal density distribution in the metallic limit. This is in agreement with the experimental statistical-studies in Pb nano-contacts. For the two analyzed cases, we show that the experimental densities are seen to be well described by the corresponding theoretical results.Comment: 6 pages, 6 figure

Coherent wave transmission in quasi-one-dimensional systems with L\'evy disorder

We study the random fluctuations of the transmission in disordered quasi-one-dimensional systems such as disordered waveguides and/or quantum wires whose random configurations of disorder are characterized by density distributions with a long tail known as L\'evy distributions. The presence of L\'evy disorder leads to large fluctuations of the transmission and anomalous localization, in relation to the standard exponential localization (Anderson localization). We calculate the complete distribution of the transmission fluctuations for different number of transmission channels in the presence and absence of time-reversal symmetry. Significant differences in the transmission statistics between disordered systems with Anderson and anomalous localizations are revealed. The theoretical predictions are independently confirmed by tight binding numerical simulations.Comment: 10 pages, 6 figure

The Impact of Social Inclusion from the Perspective of the Neurotypical Peer

This research aims to understand the benefits and overall impact of social inclusion from the perspective of the neurotypical peer. My research analyzes three strategies that are widely used to promote the acquisition of social skills for children with Autism Spectrum Disorders; Social Skills Training, Peer-Network Implementation, and Pivotal Response Training. Currently, existing research fails to thoroughly investigate how social inclusion impacts the neurotypical peer, but rather focuses on the impact that social inclusion has on the individual with ASD. While this is vital information, it is also crucial to understand from the perspective of the neurotypical peer, as they play a significant role in providing authentic, social opportunities for individuals with ASD. My research aims to close this gap and develop an understanding of social inclusion from multiple perspectives. I utilized a mixed methods approach using a combination of qualitative and quantitative data. I conducted focus group interviews, individual interviews, and observations. I included quantifiable measures such as a scale survey which was given to participants before and after the study. The ultimate goal of this study is to provide schools, and educators, with a greater understanding of social inclusion from a different perspective. As a result, we can move forward with providing our students with more meaningful inclusive opportunities. This topic is important to study due to the emphasis on mainstreaming students with special needs in the general education classroom. I will be using elements from each of the strategies described above, to develop a training program for volunteers at Grove school. Grove is a school for children ages 5-22 with behavior challenges, Autism, Cerebral Palsy, and other disabilities. The purpose of this study is to explore and understand the impact of social inclusion from the perspective of the neurotypical peer