arXiv subjects

Rhiddha Acharjee

Publications and source records attributed to Rhiddha Acharjee.

3 recordsLinked to original sources

arXiv2026

Anomalous response, re-emerging localization-transition and robust corner sates in self-similar peano fractal

Anomalous spectral response from the non-interacting electrons on a peano fractal is recorded within tight-binding framework. It is observed that a minimal off-diagonal anisotropy can modulate the transport characteristics of the lattice. Drastic modification in the nature of the eigenstates has been validated through the workout of level spacing statistics. Further, a two-dimensional quasiperiodic Aubry-André and Harper variation in the overlap integral can invite re-entrant localization-delocalization transition for the self-similar model. This is associated with the possible existence of single-particle mobility edge in the energy landscape. Our results are corroborated by the evaluation of inverse participation ratio, fractal dimension and quantum dynamical response. The spectrum is shown to formulate a quantum butterfly pattern with the frequency of the modulation. Chiral symmetry protected edge states are found to be insensitive with respect to moderate diagonal disorder.

cond-mat.other↗

arXiv2026

Reentrant localization transition, quantum butterfly and robust edge modes in aperiodic zig-zag ladder

Low dimensional tight-binding lattices in presence of quasiperiodic disorder generally exhibits localization transition. The system supports diffusive modes upto a limiting strength of disorder and all the eigenstates become localized beyond that critical strength thereby quenching the kinetic signature of the wavepacket. However, moving away from this situation, we demonstrate that with minimal long-range off-diagonal modulation, the eigenspectrum again may offer delocalization of electronic states for some subtle combination of kinetic parameters of the Hamiltonian leading to a second quantum phase change. The localization transitions are associated with the obvious presence of single-particle mobility edges. Multifractal energy landscape also shows quantum butterfly pattern with the in-gap robust edge modes. The re-emerging localization transition is manifested through the evaluation of inverse participation ratio, eigenspectrum and a pertinent quantum dynamical study.

cond-mat.other↗

arXiv2025

Localization, transport, flux induced extended modes and mobility edge in a self-similar corral substrate

We address that a single-band tight-binding Hamiltonian defined on a self-similar corral substrate can give rise to a set of non-diffusive localized modes that follow the same hierarchical distribution. As the lattice, the spatial extent of quantum prison containing a cluster of atomic sites is dependent on the generation of fractal structure. Apart from the quantum imprisonment of the excitation, a magnetic flux threading each elementary plaquette is shown to destroy the boundedness and generate an absolutely continuous sub-band populated by resonant eigen functions. Flux induced engineering of quantum states is corroborated through the evaluation of inverse participation ratio and quantum transport. Moreover, the robustness of the extended states has been checked in presence of diagonal disorder and off-diagonal anisotropy. Flux modulated single-particle mobility edge is characterized through mutlifractal analysis. Quantum interference is the essential issue, reported here, that manipulates the kinematics of the excitation and this is manifested by the workout of persistent current.

cond-mat.mes-hall↗