@article {2315, title = {Energy-level statistics in strongly disordered systems with power-law hopping}, journal = {Phys. Rev. }, volume = {B}, year = {2018}, month = {2018/07/16}, pages = {014201}, abstract = {

Motivated by neutral excitations in disordered electronic materials and systems of trapped ultracold particles with long-range interactions, we study energy-level statistics of quasiparticles with the power-law hopping Hamiltonian \∝1/rα in a strong random potential. In solid-state systems such quasiparticles, which are exemplified by neutral dipolar excitations, lead to long-range correlations of local observables and may dominate energy transport. Focussing on the excitations in disordered electronic systems, we compute the energy-level correlation function R2(ω) in a finite system in the limit of sufficiently strong disorder. At small energy differences the correlations exhibit Wigner-Dyson statistics. In particular, in the limit of very strong disorder the energy-level correlation function is given by R2(ω,V)=A3ωωV for small frequencies ω<<ωV and R2(ω,V)=1\−(α\−d)A1(ωVω)dα\−A2(ωVω)2 for large frequencies ω>>ωV, where ωV\∝V\−αd is the characteristic matrix element of excitation hopping in a system of volume V, and A1, A2 and A3 are coefficient of order unity which depend on the shape of the system. The energy-level correlation function, which we study, allows for a direct experimental observation, for example, by measuring the correlations of the ac conductance of the system at different frequencies.

}, doi = {https://doi.org/10.1103/PhysRevB.98.014201}, url = {https://arxiv.org/abs/1803.11178}, author = {Paraj Titum and Victor L. Quito and Sergey V. Syzranov} }