Statistics of Conductances and Subleading Corrections to Scaling near the Integer Quantum Hall Transition
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Autor:
H. Obuse, S. Bera, A. W. W. Ludwig, I. A. Gruzberg, F. Evers
- Quelle:
- Datum: 2013
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We study the critical behavior near the integer quantum Hall plateau transition by focusing on the multifractal (MF) exponents
Xq describing the scaling of the disorder-average moments of the point contact conductanceT between two points of the sample, within the Chalker-Coddington network model. Past analytical work has related the exponentsXq to the MF exponentsΔq of the local density of states (LDOS). To verify this relation, we numerically determine the exponentsXq with high accuracy. We thereby provide, at the same time, independent numerical results for the MF exponentsΔq for the LDOS. The presence of subleading corrections to scaling makes such determination directly from scaling of the moments ofT virtually impossible. We overcome this difficulty by using two recent advances. First, we construct pure scaling operators for the moments ofT which have precisely the same leading scaling behavior, but no subleading contributions. Secondly, we take into account corrections to scaling from irrelevant (in the renormalization group sense) scaling fields by employing a numerical technique ("stability map") recently developed by us. We thereby numerically confirm the relation between the two sets of exponents,Xq (point contact conductances) andΔq (LDOS), and also determine the leading irrelevant (corrections to scaling) exponenty as well as other subleading exponents. Our results suggest a way to access multifractality in an experimental setting.