Transmission-eigenchannel velocity and diffusion

Fuente: arXiv
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Main Authors: Genack, Azriel Z., Huang, Yiming, Maor, Asher, Shi, Zhou
Format: Preprint
Published: 2024
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author Genack, Azriel Z.
Huang, Yiming
Maor, Asher
Shi, Zhou
author_facet Genack, Azriel Z.
Huang, Yiming
Maor, Asher
Shi, Zhou
contents The diffusion model is used to calculate the time-averaged flow of particles in stochastic media and the propagation of waves averaged over ensembles of disordered static configurations. For classical waves exciting static disordered samples, such as a layer of paint or a tissue sample, the flux transmitted through the sample may be dramatically enhanced or suppressed relative to predictions of diffusion theory when the sample is excited by a waveform corresponding to a transmission eigenchannel. Even so, it is widely acknowledged that the velocity of waves is irretrievably randomized in scattering media. Here we demonstrate in microwave measurements and numerical simulations that the statistics of velocity of different transmission eigenchannels remain distinct on all length scales and are identical on the incident and output surfaces. The interplay between eigenchannel velocities and transmission eigenvalues determines the energy density within the medium, the diffusion coefficient, and the dynamics of propagation. the diffusion coefficient and all scatter9ng parameters, including the scattering mean free path, oscillate with width of the sample as the number and shape of the propagating channels in the medium change.
format Preprint
id arxiv_https___arxiv_org_abs_2401_04818
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Transmission-eigenchannel velocity and diffusion
Genack, Azriel Z.
Huang, Yiming
Maor, Asher
Shi, Zhou
Disordered Systems and Neural Networks
The diffusion model is used to calculate the time-averaged flow of particles in stochastic media and the propagation of waves averaged over ensembles of disordered static configurations. For classical waves exciting static disordered samples, such as a layer of paint or a tissue sample, the flux transmitted through the sample may be dramatically enhanced or suppressed relative to predictions of diffusion theory when the sample is excited by a waveform corresponding to a transmission eigenchannel. Even so, it is widely acknowledged that the velocity of waves is irretrievably randomized in scattering media. Here we demonstrate in microwave measurements and numerical simulations that the statistics of velocity of different transmission eigenchannels remain distinct on all length scales and are identical on the incident and output surfaces. The interplay between eigenchannel velocities and transmission eigenvalues determines the energy density within the medium, the diffusion coefficient, and the dynamics of propagation. the diffusion coefficient and all scatter9ng parameters, including the scattering mean free path, oscillate with width of the sample as the number and shape of the propagating channels in the medium change.
title Transmission-eigenchannel velocity and diffusion
topic Disordered Systems and Neural Networks
url https://arxiv.org/abs/2401.04818