Flux-Driven Circular Current in a Non-Hermitian Dimerized Aharonov–Bohm Ring: Impact of Physical Gain and Loss

Article Type

Research Article

Publication Title

Annalen Der Physik

Abstract

In the present theoretical work, magnetic response of a tight-binding (TB) dimerized ring subjected to Aharonov–Bohm (AB) flux and environmental interactions is numerically explored. Specifically, an imaginary site potential on the odd lattice sites is introduced to represent physical gain and loss, while the even lattice sites remain unperturbed. The induced current resulting from the AB flux in both real and imaginary eigenspaces, aiming to enhance this current significantly by adjusting the gain/loss parameter ((Formula presented.)) is investigated. The analysis focuses on how exceptional points in the real and imaginary eigenenergy spaces contribute to notable increases in current at specific (Formula presented.) values, and the emergence of purely real current when the imaginary current vanishes. How the dual behavior of energy spectrum (real and imaginary), converging to and diverging from zero energy, affects the enhancement of the current is discussed. Additionally, the interplay between the correlations of dimerized hopping integrals and the gain-loss parameter, which affects the current and highlights key features associated with these physical parameters, is studied. Furthermore, how system size impacts the findings is considered. The study may reveal unconventional characteristics in various loop configurations, potentially paving the way for new research directions.

DOI

10.1002/andp.202500217

Publication Date

12-1-2025

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