arXiv subjects

Joydeep Majhi

Publications and source records attributed to Joydeep Majhi.

5 recordsLinked to original sources

arXiv2026

Compact localized states and magnetic flux-driven topological phase transition in a diamond-dodecagon lattice geometry

We propose and investigate a novel two-dimensional (2D) tight-binding model defined on a diamond-dodecagon lattice geometry that hosts multiple flat bands (FBs) and supports topological phase transitions driven by a magnetic flux. This lattice exhibits three completely flat, non-dispersive bands in the band structure in the absence of magnetic flux due to destructive interference in the electron hoppings, leading to the emergence of compact localized states (CLS). These CLS are analytically constructed and exhibit real-space confinement of the electrons, arising solely due to the lattice's geometrical frustration. It has been shown that these FBs are very robust against the introduction of weak random onsite disorder in the system. By tuning the uniform magnetic flux threaded through the diamond plaquettes, we demonstrate a tunable evolution of the band structure and show that certain bands develop nontrivial topological features with nonzero integer values of the Chern number. Additionally, we have computed the multi-terminal transport properties for this 2D lattice system, which display the flux-tunable resonances and transmission suppression linked to the FBs, establishing a clear interplay between the localization, topology, and transport. Our findings put forward the diamond-dodecagon lattice as a robust and tunable platform for studying the flat-band physics and magnetic flux-controlled topological phenomena, offering promising experimental feasibility in photonic lattices and ultracold atomic systems.

cond-mat.str-el↗

arXiv2024

Modulation of charge and spin circular currents in a ring-wire hybrid setup

We present a comprehensive investigation into the charge and spin circular currents in a mesoscopic hybrid system, with a particular focus on the intricate interplay between the Aubry-Andr\'e-Harper (AAH) potential, Aharonov-Bohm (AB) flux, chemical potential ($\mu$), and antiferromagnetic (AF) ordering. The proposed quantum system comprises a composite structure of an AF ring coupled to an AAH chain. Utilizing a tight-binding model and operator method to calculate charge and spin circular currents, we uncover a range of intriguing phenomena. An interesting finding is that while the antiferromagnetic ring alone does not exhibit spin channel separation due to the symmetry between the up and down spin sub-Hamiltonians, the introduction of a dangling bond or chain can break this symmetry, leading to a spin separation effect. The AAH potential in the chain disrupts energy level symmetry, significantly impacting transport behavior. The charge circular current exhibits periodic oscillations with the AB flux, and its polarity changes with variations in $\mu$. The AAH phase affects the charge current through the shifting of energy levels. Furthermore, the spin current displays oscillatory behavior as the AAH potential strength changes, with peaks emerging due to interference phenomena caused by disorder-induced localization. A possible experimental realization of our proposed quantum setup is also discussed, for the sake of completeness. This work may provide important insights into the complex physics of charge and spin transport in various hybrid mesoscopic systems, offering promising avenues for future research and technological applications.

cond-mat.mes-hall↗

arXiv2023

Uncertainty Relations for the Relativistic Jackiw-Nair Anyon: A First Principles Derivation

In this paper we have explicitly computed the $position-position$ and $position-momentum$ (Heisenberg) Uncertainty Relations for the model of relativistic particles with arbitrary spin, proposed by Jackiw and Nair ref.[1] as a model for Anyon, in a purely quantum mechanical framework. This supports (via Schwarz inequality) the conjecture that anyons live in a 2-dimensional \textit{noncommutative} space. We have computed the non-trivial uncertainty relation between anyon coordinates, ${\sqrt{Δx^2Δy^2}}=\hbar\barΘ_{xy}$, using the recently constructed anyon wave function ref.[6], in the framework of ref.[7]. We also compute the Heisenberg (position-momentum) uncertainty relation for anyons. Lastly we show that the identical \textit{formalism} when applied to electrons, yield a trivial position uncertainty relation, consistent with their living in a 3-dimensional commutative space.

hep-th↗

arXiv2021

Enhanced current rectification in graphene nanoribbons: Effects of geometries and orientations of nanopores

We discuss the possibility of getting rectification operation in graphene nanoribbon (GNR). For a system to be a rectifier, it must be physically asymmetric and we induce the asymmetry in GNR by introducing nanopores. The rectification properties are discussed for differently structured nanopores. We find that shape and orientation of the nanopores are critical and sensitive to the degree of current rectification. As the choice of Fermi energy is crucial for obtaining significant current rectification, explicit dependence of Fermi energy on the degree of current rectification is also studied for a particular shape of the nanopore. Finally, the role of nanopore size and different spatial distributions of the electrostatic potential profile across the GNR are discussed. Given the simplicity of the proposed method and promising results, the present proposition may lead to a new route of getting current rectification in different kinds of materials where nanopores can be formed selectively.

cond-mat.mes-hall↗

arXiv2019

Relativistic Anyon Beam: Construction and Properties

Motivated by recent interest in photon and electron vortex beams, we propose the construction of a relativistic anyon beam. Following Jackiw and Nair [Phys. Rev. D 43, 1933 (1991)] we derive explicit form of relativistic plane wave solution of a single anyon. Subsequently we construct the planar anyon beam by superposing these solutions. Explicit expressions for the conserved anyon current are derived. Finally, we provide expressions for the anyon beam current using the superposed waves and discuss its properties. We also comment on the possibility of laboratory construction of anyon beam.

hep-th↗