Quantum Transparency of Anderson Insulator Junctions: Statistics of Transmission Eigenvalues, Shot Noise, and Proximity Conductance
arXiv:cond-mat/0404271 · doi:10.1103/PhysRevB.71.045308
Abstract
We investigate quantum transport through strongly disordered barriers, made of a material with exceptionally high resistivity that behaves as an Anderson insulator or a ``bad metal'' in the bulk, by analyzing the distribution of Landauer transmission eigenvalues for a junction where such barrier is attached to two clean metallic leads. We find that scaling of the transmission eigenvalue distribution with the junction thickness (starting from the single interface limit) always predicts a non-zero probability to find high transmission channels even in relatively thick barriers. Using this distribution, we compute the zero frequency shot noise power (as well as its sample-to-sample fluctuations) and demonstrate how it provides a single number characterization of non-trivial transmission properties of different types of disordered barriers. The appearance of open conducting channels, whose transmission eigenvalue is close to one, and corresponding violent mesoscopic fluctuations of transport quantities explain at least some of the peculiar zero-bias anomalies in the Anderson-insulator/superconductor junctions observed in recent experiments [Phys. Rev. B {\bf 61}, 13037 (2000)]. Our findings are also relevant for the understanding of the role of defects that can undermine quality of thin tunnel barriers made of conventional band-insulators.
arXiv comment9 pages, 8 color EPS figures; one additional figure on mesoscopic fluctuations of Fano factor
References in corpus (13)
- Shot Noise in Mesoscopic Conductors
- Random-Matrix Theory of Quantum Transport
- Typical medium theory of Anderson localization: A local order parameter approach to strong disorder effects
- Reflectionless Tunneling Through a Double-Barrier NS Junction
- Universal distribution of transparencies in highly conductive Nb/AlO/Nb junctions
- Decay Rate Distributions of Disordered Slabs and Application to Random Lasers
- Tuning a Josephson junction through a quantum critical point
- Quantum transport in ballistic conductors: evolution from conductance quantization to resonant tunneling
- Resistivity of a Metal between the Boltzmann Transport Regime and the Anderson Transition
- Reduction of Josephson critical current in short ballistic SNS weak links
- Quest for Rare Events in three-dimensional Mesoscopic Disordered Metals
- Theory of Andreev reflection in a junction with a strongly disordered semiconductor
- Crossover from tunneling to incoherent (bulk) transport in a correlated nanostructure