A5021027571- Mechanical and Optical Resonators
- Photonic and Optical Devices
- Advanced MEMS and NEMS Technologies
- Force Microscopy Techniques and Applications
- Acoustic Wave Resonator Technologies
- Carbon Nanotubes in Composites
- Graphene research and applications
- Nanopore and Nanochannel Transport Studies
- Semiconductor Quantum Structures and Devices
- Advanced biosensing and bioanalysis techniques
- Semiconductor materials and devices
- Advancements in Semiconductor Devices and Circuit Design
- Advanced Fiber Laser Technologies
- 2D Materials and Applications
- Plasmonic and Surface Plasmon Research
- RNA Interference and Gene Delivery
- Integrated Circuits and Semiconductor Failure Analysis
- Conducting polymers and applications
- Molecular Junctions and Nanostructures
- Semiconductor Lasers and Optical Devices
- Analytical Chemistry and Sensors
- Advanced Semiconductor Detectors and Materials
- Advanced Sensor and Energy Harvesting Materials
- Organic Electronics and Photovoltaics
- GaN-based semiconductor devices and materials
Indian Institute of Science Bangalore
2016-2025
Technology Centre Prague
2024
Solid State Physics Laboratory
1995-2023
University of South Alabama
2013
California Institute of Technology
2009-2012
Physical Sciences (United States)
2007
Iowa State University
2001
Ames National Laboratory
2001
Abstract One of the main challenges to overcome perform nanomechanical mass spectrometry analysis in a practical time frame stems from size mismatch between analyte beam and small detector area. We report here demonstration with arrays 20 multiplexed resonators; each resonator is designed distinct resonance frequency which becomes its individual address. Mass spectra metallic aggregates MDa range are acquired more than one order magnitude improvement compared resonators. A NEMS array probed...
Atomically thin two dimensional (2D) layered materials have emerged as a new class of material for nanoelectromechanical systems (NEMS) due to their extraordinary mechanical properties and ultralow mass density. Among them, graphene has been the choice nanomechanical resonator. However, recent interest in 2D chalcogenide compounds also spurred research using such MoS2 NEMS applications. As dimensions devices fabricated these shrink down atomically membrane, strain nonlinear effects become...
The steady-state photoinduced absorption (PA), photoluminescence (PL), PL-detected magnetic resonance (PLDMR), and PA-detected (PADMR) of poly- oligo-(para-phenylenes) films is described. In particular, the excitation density (laser power) ${N}_{0}$ dependence PA, PL, PLDMR signals analyzed by means a rate equation model, which describes dynamics singlet excitons (SE's) polarons in all three experiments quantitatively with same set parameters. model based on observations that mobile SE's are...
We consider time dynamics of entanglement entropy between a filled fermionic system and an empty reservoir. scenarios (i) where the is subjected to dephasing mechanism reservoir clean, thereby emulating expansion effectively interacting fermions in vacuum, (ii) both are enabling us address how part its complement evolves time. two different kinds quantum trajectory approaches, namely stochastic unitary unraveling state diffusion. For protocols, we observe characterize full Page curve-like...
Abstract Single photon emitters (SPEs) are building blocks of quantum technologies. Defect engineering two‐dimensional (2D) materials is ideal to fabricate SPEs, wherein spatially deterministic and quality‐preserving fabrication methods critical for integration into devices cavities. Existing use combination strain electron irradiation, or ion which make complex, limited by surrounding lattice damage. Here, only ultra‐low energy beam (e‐beam) irradiation (5 keV) utilized create dilute defect...
Phase change materials (PCMs) with distinct optical properties at different phases are promising candidates for programmable photonics, communication and photonic computing. In this work, we have studied thermo-optic effect in a PCM-based integrated device comprising film of bistable [Fe2Co2] molecular square complex Prussian Blue Analogues deposited on an on-chip silicon slot waveguide micro-ring resonator. Herein, reporting large blue-shift 200 pm/K corresponding to coefficient −0.4 RIU/K...
Nonlinearities in nanoelectromechanical systems (NEMS) play a vital role dynamics of the device. Clear understanding nonlinearities and ability to tune manipulate them enhance performance are crucial for applications with these devices. Here, we utilize an electrostatic mechanism geometric nonlinearity atomically thin NEMS. The exquisite tuning enables us demonstrate hardening, softening, mixed nonlinear responses over is utilized effectively nullify Duffing specific regime. observed...
Parametric amplification in a MoS<sub>2</sub> drum resonator and the effect of Duffing non-linearity on parametric amplitude gain.
From sensing perspective, smaller electromechanical devices, in general, are expected to be more responsive the stimuli. This enhanced performance, however, is contingent upon noise sources remaining unchanged and onset of nonlinear behavior not being precipitated by miniaturization. In this paper, we study effect strain on nonlinearities dynamic range graphene nanoresonators. The response nonlinearity these devices sensitive both electrostatic field used actuate device strain. By tuning two...
Field emission of carbon nanotubes (CNTs) was remarkably improved by lanthanum-hexaboride (LaB6) nano-particles (NPs) decoration. CNTs were grown on the silicon substrate chemical vapor deposition. bare and LaB6-NPs decorated carried out under same conditions. Physical, morphological, elemental, graphitic nature changes ascertained scanning electron microscope, transmission energy dispersive x-ray spectroscopy, Raman analysis. show significant reduction turn-on electric-field from 3.0 to 2.1...
Coupling between a mechanical resonator and optical cavities, microwave resonators, or other resonators have been used to observe interesting effects from sideband cooling coherent manipulation of phonons. Here we demonstrate strong coupling different vibrational modes MoS2 drum at room temperature. We intermodal as well intramodal coupling. Cooperativity, measure the two modes, can be tuned by more than an order magnitude changing direct current gate bias. The large measured cooperativity...
Pore functionalization has been explored by several groups as a strategy to control DNA translocation through solid-state nanopores. Here we present hybrid nanopore system consisting of single-layer graphene and origami layer achieve base-selective rate aligned nanopores the two layers. This is achieved incorporating unpaired dangling bases called overhangs near pore region. Molecular dynamics simulations were used optimize design overhangs. Specifically, considered influence number spatial...
Cost-effective, fast, and reliable DNA sequencing can be enabled by advances in nanopore-based methods, such as the use of atomically thin graphene membranes. However, strong interaction bases with leads to undesirable effects sticking strands membrane surface. While surface functionalization is one way counter this problem, here, we present another solution based on a heterostructure nanopore system, consisting monolayer hexagonal boron nitride (hBN) each. Molecular dynamics studies...
Bifurcation amplifiers are known for their extremely high sensitivity to weak input signals. We implement a bifurcation amplifier by harnessing the Duffing nonlinearity in parametrically excited MoS2 nano-electromechanical system. utilize ultra-sensitive switching response between two states of detect as well register charge-fluctuation events. demonstrate open-loop real-time detection ultra-low electrical charge perturbations magnitude &lt;10 e at room temperature. Furthermore, we show...
We describe the single-molecule sensing of G-quadruplex (G-q) formation in target-bound aptamers using solid-state nanopores. In order to do this, we functionalize nanopore DNA origami sheets incorporated with aptamer sequence. This provides a modular configuration for nanopore-based sensors where changing sequence can produce required functionalization nanopore. Furthermore, sheet also contains pore which modulate translocation dynamics target molecule through Using this system, show that...
This work evaluates the performance of carbon nanotube field-effect transistors (CNTFETs) using few layer graphene as contact electrode material. We present experimental results barrier height at nanotube-graphene junction temperature dependent I-V measurements. The estimated in our devices for both holes and electrons is close to zero indicating ohmic p-type n-type CNTFETs thus demonstrating suitability material CMOS-type circuits based on CNTFETs. Furthermore, we observe that there no...
We demonstrate all electrical measurements on NEMS devices fabricated using CVD grown monolayer MoS2. The as-grown film of MoS2 top the SiO2/Si wafer is processed to fabricate arrays and individual without complex pick transfer techniques associated with graphene. electromechanical properties are par those exfoliation method. frequency response these then used as a probe estimate linear thermal expansion coefficient material evaluate effect strain effective Duffing nonlinearity in devices.
A superconducting Coulomb-blockade electrometer was used to measure the Coulomb staircase of an $\mathrm{Al}∕\mathrm{Al}{\mathrm{O}}_{x}∕\mathrm{Al}$ Cooper-pair box from a temperature $30\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}300\phantom{\rule{0.3em}{0ex}}\mathrm{mK}$. At lowest temperature, displays effects nonequilibrium quasiparticles. As is increased, initial decrease found in width odd steps staircase, which corresponds reduction probability having quasiparticle...