A5085342660- Quantum and electron transport phenomena
- Molecular Junctions and Nanostructures
- Magnetic properties of thin films
- Physics of Superconductivity and Magnetism
- Topological Materials and Phenomena
- Graphene research and applications
- Advanced Thermoelectric Materials and Devices
- Advancements in Semiconductor Devices and Circuit Design
- Semiconductor Quantum Structures and Devices
- Quantum-Dot Cellular Automata
- Organic Electronics and Photovoltaics
- Surface and Thin Film Phenomena
- Semiconductor materials and devices
- Force Microscopy Techniques and Applications
- Thermal properties of materials
- Quantum optics and atomic interactions
- Spectroscopy and Quantum Chemical Studies
- Theoretical and Computational Physics
- 2D Materials and Applications
- Quantum many-body systems
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Chemical Physics Studies
- Advanced Physical and Chemical Molecular Interactions
- Electrochemical Analysis and Applications
- Quantum chaos and dynamical systems
Indian Statistical Institute
2016-2025
Friedrich-Alexander-Universität Erlangen-Nürnberg
2023
University of Science and Technology, Meghalaya
2022
Saha Institute of Nuclear Physics
2004-2013
Tel Aviv University
2012-2013
University of Rochester
1990
We prove that a tight-binding ladder network composed of atomic sites with on-site potentials distributed according to the quasiperiodic Aubry model can exhibit metal-insulator transition at multiple values Fermi energy. For specific first and second neighbor electron hopping, result is obtained exactly. With more general model, we numerically calculate two-terminal conductance. The numerical results corroborate analytical findings.
We propose two new approaches for regulating spin polarization and inversion in a conducting junction within tight-binding framework based on wave-guide theory. The system comprises magnetic quantum ring with finite modulation site potential is coupled to non-magnetic electrodes. Due close proximity an additional tunneling established between the electrodes which regulates electronic transmission significantly. At same time phase associated potential, can be tuned externally yields...
Localization in one-dimensional disordered or quasiperiodic noninteracting systems the presence of power-law hopping is very different from localization short-ranged systems. Power-law leads to algebraic as opposed exponential Exponential synonymous with insulating behavior thermodynamic limit. Here we show that same not true for localization. We show, on general grounds, depending strength decay, algebraically localized states can be actually either conducting exemplify this statement...
We investigate the possibilities of a tight-binding ladder network as mesoscopic switching device. Several cases have been discussed in which any one or both arms can assume random, ordered, quasiperiodic distribution atomic potentials. show that, for special choice Hamiltonian parameters, it is possible to prove exactly existence mobility edges such system, plays central role action. also present numerical results two-terminal conductance general model quasiperiodically grown ladder,...
Electronic transport in a one-dimensional mesoscopic ring threaded by magnetic flux is studied the presence of Rashba and Dresselhaus spin-orbit interactions. A completely analytical technique within tight-binding formalism unveils spin-split bands interactions leads to method determining strength interaction. In addition this, persistent currents for ordered disordered rings have been investigated numerically. It observed that interaction, general, an enhanced amplitude current. Numerical...
In the present work, possibility of regulating local magnetic field in a quantum ring is investigated theoretically. The coupled to wire and subjected an in-plane electric field. Under finite bias voltage across net circulating current established which produces strong at its centre. This can be tuned externally wide range by field, thus, our system utilized control specific region. feasibility this designing spin-based devices also analyzed.
Magnetic helix (MH) structure can be a role model for future spintronic devices. Utilizing the advantage of constructing possible magnetic configurations, in this work we investigate behavior helical geometry with finite ordering. The interplay between short- and long-range hopping electrons yields many nontrivial features which are thoroughly studied. Quite interestingly, see that MH exhibits strong chiral-induced spin-selectivity effect, like what is observed chiral molecules. Finally, to...
Reentrant localization (RL), a recently prominent phenomenon, traditionally links to the interplay of staggered correlated disorder and hopping dimerization, as indicated by prior research. Contrary this paradigm, our present study demonstrates that dimerization is not pivotal factor in realizing RL. Considering helical magnetic system with antiferromagnetic ordering, we uncover spin-dependent RL at multiple energy regions, absence dimerization. This phenomenon persists even thermodynamic...
This work explores spin filtration in a helical magnetic system within tight-binding framework, where neighboring moments are aligned antiparallel. The helix experiences slowly-varying diagonal disorder, following cosine form, which creates finite energy mismatch between up and down channels. Unlike earlier studies that relied on external electric fields, this investigation demonstrates disorder alone can achieve high filtration, even at low bias temperatures. Higher-order electron hopping...
We propose, for the first time, that an array of diamond plaquettes, each possessing vanishing net magnetization, can achieve complete spin polarization over a broad bias window. Furthermore, this system be utilized to realize spin-specific semiconducting behavior. describe antiferromagnetic network within tight-binding framework, where spin-dependent scattering arises due interaction between itinerant electrons and local magnetic moments at different lattice sites. The mechanism underlying...
We demonstrate elastically filtered 3D Electron Diffraction (3D ED) as a powerful alternative technique to Grazing Incidence Wide-Angle X-ray Scattering (GIWAXS) for quantitatively characterizing the structure of organic semiconductor films. Using model material system solvent vapor annealed DRCN5T:PC71BM thin film, which is employed in solar cells (OSCs), we extract structural data obtained from ED and compare with that GIWAXS, utilizing both laboratory synchrotron sources. Quantitative...
The specific role of environmental interaction on bias driven circular current in a ring nanojunction is explored within tight-binding framework based wave-guide theory. implemented through disorder backbone sites where these are directly coupled to parent lattice the via single bonds. In absence disorder, becomes zero for lengthwise symmetric nanojunction, while it increases with which quite unusual, and after reaching maximum, eventually drops limit high disorder. effects ring-electrode...
Spin dependent transport in a multi-terminal mesoscopic ring is investigated presence of Rashba and Dresselhaus spin-orbit interactions. Within tight-binding framework, we use general spin density matrix formalism to evaluate all three components (Px, Py, Pz) the polarization vector associated with charge current through outgoing leads. It explores dynamics propagating system subjected and/or couplings. The sensitivity on electrode-ring interface geometry discussed detail. Our present...
We address spin dependent transport through an array of diamonds in the presence Rashba spin-orbit (SO) interaction where each diamond plaquette is penetrated by Aharonov-Bohm (AB) flux $\phi$. The chain attached symmetrically to two semi-infinite one-dimensional non-magnetic metallic leads. adopt a single particle tight-binding Hamiltonian describe system and study using Green's function formalism. After presenting analytical method for energy dispersion relation infinite SO interaction, we...
Exploiting spin degree of freedom electron a new proposal is given to characterize spin-based logical operations using quantum interferometer that can be utilized as programmable logic device (PSLD). The ON and OFF states both inputs outputs are described by state only, circumventing spin-to-charge conversion at every stage often used in conventional devices with the inclusion extra hardware eventually diminish efficiency. All possible functions engineered from single without redesigning...