Browsing School of Physics by Sponsor "Science Foundation Ireland"
Now showing items 1-20 of 140
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1.3 μm wavelength tunable single-mode laser arrays based on slots
(2021)Two twelve-channel arrays based on surface-etched slot gratings, one with non-uniformly spaced slots and another with uniformly spaced slots are presented for laser operation in the O-band. A wavelength tuning range greater ... -
1/f noise in MgO double-barrier magnetic tunnel junctions
(2011)Low frequency noise has been investigated in MgO double-barrier magnetic tunnel junctions (DMTJs) with tunneling magnetoresistance (TMR) ratios up to 250% at room temperature. The noise shows a 1/f frequency spectrum and ... -
850 nm GaAs/AlGaAs DFB lasers with shallow surface gratings and oxide aperture
(2019)We present and experimentally demonstrate a novel oxide-confined ridge-waveguide distributed feedback (DFB) laser with the first-order surface grating using only a single growth step. The metal contacts are laterally offset ... -
Analysis of slot characteristics in single mode semiconductor lasers using the 2D scattering matrix method
(IEEE, 2006)We use the two-dimensional (2-D) scattering matrix method (SMM) to analyze the slot characteristics in slotted single-mode semiconductor lasers and compare the results with those calculated by the one-dimensional transfer ... -
Analysis of the conditional mutual information in ballistic and diffusive non-equilibrium steady-states
(2020)The conditional mutual information (CMI) ℐ(A:C|B) quantifies the amount of correlations shared between A and C given B. It therefore functions as a more general quantifier of bipartite correlations in multipartite scenarios, ... -
Annealing effect on tunneling magnetoresistance in MgO-based magnetic tunnel junctions with FeMn exchange-bias layer
(2010)MgO-based magnetic tunnel junctions were fabricated, with a thin pinned CoFeB layer in the unbalanced synthetic antiferromagnet part of the stack FeMn/CoFe/Ru/CoFeB. Inverted and normal tunneling magnetoresistance (TMR) ... -
Annealing of CoFeB/MgO based single and double barrier magnetic tunnel junctions: Tunnel magnetoresistance, bias dependence, and output voltage
(American Institute of Physics, 2009)Co40Fe40B20/MgO single and double barrier magnetic tunnel junctions (MTJs) were grown using target-facing-target sputtering for MgO barriers and conventional dc magnetron sputtering for Co40Fe40B20 ferromagnetic electrodes. ... -
Anomalous anisotropic magnetoresistance in epitaxial Fe3O4 thin films on MgO (100)
(American Physical Society, 2008-12)Studies of the angular dependence of the anisotropic magnetoresistance (AMR) are reported for epitaxial films of magnetite (Fe3O4) grown on MgO(001) and also for single crystals of magnetite. The characteristic feature of ... -
An apparatus and methodology for high-power SQUID-detected ferromagnetic resonance measurements
(2019)Historically, ferromagnetic resonance has been dominated by inductive techniques, for the best part of the last 80 years. It has been only in the last 20 years that non-inductive techniques, such as Ferromagnetic Resonance ... -
Asymmetry in energy versus spin transport in certain interacting disordered systems
(2019)We study energy transport in disordered XXZ spin-1/2 chains driven to nonequilibrium configurations by thermal reservoirs of different temperatures at the boundaries, using large-scale matrix product simulations. In ... -
Athermalisation and Characterisation of High-OrderSurface Grating Lasers for Optical Communications
(Trinity College Dublin. School of Physics. Discipline of Physics, 2023)The semiconductor laser allows for the vast quantities of data that are transmitted over optical fibre each day. A simple device has transformed our lives. This transformation will continue in the coming decade where ... -
Ballistic vs diffusive low-frequency scaling in the XXZ and a locally perturbed XXZ chain
(2020)We study the matrix elements of local operators in the eigenstates of the integrable XXZ chain and of the quantum-chaotic model obtained by locally perturbing the XXZ chain with a magnetic impurity. We show that, at ... -
Bias voltage dependence of inverted magnetoresistance on the annealing temperature in MgO-based magnetic tunnel junctions
(Elsevier, 2009)MgO-based magnetic tunnel junctions (MTJs) with a layer sequence Ir22Mn78 or Fe50Mn50 (10 nm)/CoFe (2 nm)/Ru (0.85 nm)/CoFeB (0.5t<2 nm)/MgO (2.5 nm)/CoFeB (3 nm) have been fabricated. The bias voltage dependence of tunneling ... -
Calculation of model Hamiltonian parameters for LaMnO3 using maximally localized Wannier functions
(2010)In this work we demonstrate that maximally localized Wannier functions (MLWFs) based on Kohn-Sham band structures provide a very robust and systematic way to construct realistic, materials-specific tight-binding models for ... -
CALPHAD-assisted development of in-situ nanocrystallised melt-spun Co-Fe-B alloy with high Bs (1.57 T)
(2021)A thermodynamics-based approach, Calculation of Phase Diagram (CALPHAD), combined with topological instability parameters are proposed and experimentally evaluated, in order to optimise in-situ nanocrystallisation of rapidly ... -
Chirality of electrodeposits grown in a magnetic field
(American Physical Society, 2004)Electrodeposits grown around a point cathode in a flat, horizontal electrochemical cell have fractal form. When grown in the presence of a perpendicular applied magnetic field, the deposits develop a spiral structure with ... -
Comprehenisive characterization of molecular interactions based on nanomechanics
(2008)Molecular interaction is a key concept in our understanding of the biological mechanisms of life. Two physical properties change when one molecular partner binds to another. Firstly, the masses combine and secondly, the ... -
Confined optical modes and amplified spontaneous emission from a microtube cavity formed by vacumm assisted filtration
(American Physical Society, 2006)The authors demonstrate a new route to the fabrication of individual aluminosilicate microtubes that can act as micron-scale optical cylindrical resonators. The microtubes were prepared using a simple vacuum assisted wetting ... -
Controlled fabrication of nickel perpendicular nanocontacts using focused ion beam milling
(American Institute of Physics, 2006)A method for the controlled fabrication of a nickel perpendicular nanocontact with diameters less than 5 nm is reported. The method involves milling pores through the 100 nm thick silicon nitride membrane using a focused ...