arXiv subjects

Keith Slevin

Publications and source records attributed to Keith Slevin.

44 records · Page 3Linked to original sources

arXiv2001

Reconciling Conductance Fluctuations and the Scaling Theory of Localization

We reconcile the phenomenon of mesoscopic conductance fluctuations with the single parameter scaling theory of the Anderson transition. We calculate three averages of the conductance distribution: $\exp(<\ln g>)$, $ $ and $1/ $ where $g$ is the conductance in units of $e^2/h$ and $R=1/g$ is the resistance and demonstrate that these quantities obey single parameter scaling laws. We obtain consistent estimates of the critical exponent from the scaling of all these quantities.

cond-mat.dis-nn↗

arXiv2001

Numerical verification of universality for the Anderson transition

We analyze the scaling behavior of the higher Lyapunov exponents at the Anderson transition. We estimate the critical exponent and verify its universality and that of the critical conductance distribution for box, Gaussian and Lorentzian distributions of the random potential.

cond-mat.dis-nn↗

arXiv2000

Topology dependent quantities at the Anderson transition

The boundary condition dependence of the critical behavior for the three dimensional Anderson transition is investigated. A strong dependence of the scaling function and the critical conductance distribution on the boundary conditions is found, while the critical disorder and critical exponent are found to be independent of the boundary conditions.

cond-mat.dis-nn↗

arXiv1999

Review of recent progress on numerical studies of the Anderson transition

A review of recent progress in numerical studies of the Anderson transition in three dimensional systems is presented. From high precision calculations the critical exponent $ν$ for the divergence of the localization length is estimated to be $ν=1.57\pm 0.02$ for the orthogonal universality class, which is clearly distinguished from $ν=1.43\pm 0.03$ for the unitary universality class. The boundary condition dependences of some quantities at the Anderson transition are also discussed.

cond-mat.mes-hall↗

arXiv1998

Corrections to scaling at the Anderson transition

We report a numerical analysis of corrections to finite size scaling at the Anderson transition due to irrelevant scaling variables and non-linearities of the scaling variables. By taking proper account of these corrections, the universality of the critical exponent for the orthogonal universality class for three different distributions of the random potential is convincingly demonstrated.

cond-mat.dis-nn↗

arXiv1998

Universal conductance distribution in three dimensional systems in high magnetic fields

The nature of the critical point of the Anderson transition in high magnetic fields is discussed with an emphasis on scale invariance and universality of the critical exponent. Special attention is paid to the distribution function of the conductance which becomes size and model independent at the critical point. The fractal properties of the wave function which are related to scale invariance are also discussed.

cond-mat.mes-hall↗

arXiv1997

The Anderson transition: time reversal symmetry and universality

We report a finite size scaling study of the Anderson transition. Different scaling functions and different values for the critical exponent have been found, consistent with the existence of the orthogonal and unitary universality classes which occur in the field theory description of the transition. The critical conductance distribution at the Anderson transition has also been investigated and different distributions for the orthogonal and unitary classes obtained.

cond-mat.dis-nn↗

arXiv1996

Quantum interference and the spin orbit interaction in mesoscopic normal-superconducting junctions

We calculate the quantum correction to the classical conductance of a disordered mesoscopic normal-superconducting (NS) junction in which the electron spatial and spin degrees of freedom are coupled by an appreciable spin orbit interaction. We use random matrix theory to describe the scattering in the normal part of the junction and consider both quasi-ballistic and diffusive junctions. The dependence of the junction conductance on the Schottky barrier transparency at the NS interface is also considered. We find that the quantum correction is sensitive to the breaking of spin rotation symmetry even when the junction is in a magnetic field and time reversal symmetry is broken. We demonstrate that this sensitivity is due to quantum interference between scattering processes which involve electrons and holes traversing closed loops in the same direction. We explain why such processes are sensitive to the spin orbit interaction but not to a magnetic field. Finally we consider the effect of the spin orbit interaction on the phenomenon of ``reflectionless tunnelling.''

cond-mat↗