English

More scaling limits for 1d random Schr\"odinger operators with critically decaying and vanishing potentials

Probability 2026-03-27 v2 Mathematical Physics math.MP

Abstract

Consider the random Schr\"odinger operator HnH_n defined on {0,1,,n}Z\{0,1,\cdots,n\}\subset\mathbb{Z} (Hnψ)=ψ1,n+ψ+1,n+σωa,nψ,n,ψ0=ψn+1=0, (H_n\psi)_\ell=\psi_{\ell-1,n}+\psi_{\ell+1,n}+\sigma\frac{\omega_\ell}{a_{\ell,n}}\psi_{\ell,n},\quad \psi_0=\psi_{n+1}=0, where σ>0\sigma>0, ω\omega_\ell are i.i.d. random variables and a,na_{\ell,n} typically has order n\sqrt{n} for [ϵn,(1ϵ)n]\ell\in[\epsilon n,(1-\epsilon)n] and any ϵ>0\epsilon>0. Two important cases: (a) the vanishing case a,n=na_{\ell,n}=\sqrt{n} and (b) the decaying case a,n=a_{\ell,n}=\sqrt{\ell}, were studied before in \cite{kritchevski2011scaling}. In this paper we consider more general decaying profiles that lie in between these two extreme cases. We characterize the scaling limit of transfer matrices and determine the point process limit of eigenvalues near a fixed energy in the bulk, in terms of solutions to coupled SDEs. We obtain new point processes that share similar properties to the Schτ\text{Sch}_\tau process. We determine the shape profile of eigenfunctions after a suitable rescaling, that corresponds to a uniformly chosen eigenvalue of HnH_n. We also give a more detailed description of the newly defined point processes, including the probability of small and large gaps and a variance estimate.

Keywords

Cite

@article{arxiv.2305.08205,
  title  = {More scaling limits for 1d random Schr\"odinger operators with critically decaying and vanishing potentials},
  author = {Yi Han},
  journal= {arXiv preprint arXiv:2305.08205},
  year   = {2026}
}

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22 pages