160 Matching Results

Results open in a new window/tab.

An Extreme X-Ray Variability Event of a Weak-line Quasar (open access)

An Extreme X-Ray Variability Event of a Weak-line Quasar

Article reports the discovery of an extreme X-ray flux rise (by a factor of ≳20) of the weak-line quasar Sloan Digital Sky Survey (SDSS) J153913.47+395423.4 (hereafter SDSS J1539+3954) at z = 1.935. SDSS J1539+3954 is the most-luminous object among radio-quiet type 1 active galactic nuclei (AGNs) where such dramatic X-ray variability has been observed.
Date: February 3, 2020
Creator: Ni, Q.; Brandt, W. N.; Yi, W.; Luo, B.; Timlin, J. D., III; Hall, P. B. et al.
Object Type: Article
System: The UNT Digital Library
Phononic crystal as a homogeneous viscous metamaterial (open access)

Phononic crystal as a homogeneous viscous metamaterial

Article develops a homogenization theory, representing the low-frequency limit for a phononic crystal of cylinders embedded in a viscous fluid.
Date: June 8, 2020
Creator: Krokhin, Arkadii A.; Zubov, Yu.; Ibarias, M. & Arriaga, J.
Object Type: Article
System: The UNT Digital Library
Continuum models of the electrochemical diffuse layer in electronic-structure calculations (open access)

Continuum models of the electrochemical diffuse layer in electronic-structure calculations

This article presents a critical comparison of continuum diffuse-layer models that can be coupled to an atomistic first-principles description of the charged metal surface in order to account for the electrolyte screening at electrified interfaces.
Date: August 31, 2018
Creator: Nattino, Francesco; Truscott, Matthew; Marzari, Nicola & Andreussi, Oliviero
Object Type: Article
System: The UNT Digital Library
Influence of coherent population trapping on Raman scattering (open access)

Influence of coherent population trapping on Raman scattering

Article considering the Raman scattering in molecular media. Applying two laser fields in a two-photon resonance with vibrational transition, the authors study the role of rotational levels for excitation of vibrational coherence. It is shown that the molecular vibrational coherence strongly depends on the effect of coherent population trapping for rotational levels. The obtained results are important for applications of Raman spectroscopy to molecular detection in engineering, chemical, and biological applications.
Date: August 8, 2019
Creator: Singh, Pooja; Rostovtsev, Yuri V.; Patnaik, Anil K.; Roy, Sukesh & Gord, James R.
Object Type: Article
System: The UNT Digital Library
Fe/GeTe(111) heterostructures as an avenue towards spintronics based on ferroelectric Rashba semiconductors (open access)

Fe/GeTe(111) heterostructures as an avenue towards spintronics based on ferroelectric Rashba semiconductors

Article investigating the electronic structure of Fe/GeTe(111), a prototypical ferromagnetic/Rashba-ferroelectric interface, by performing density functional theory and Green's functions calculations complemented by x-ray photoemission spectroscopy.
Date: February 19, 2019
Creator: Sławińska, Jagoda; Di Sante, Domenico; Varotto, Sara; Rinaldi, Christian & Picozzi, Silvia
Object Type: Article
System: The UNT Digital Library
Persistent spin helix in Rashba-Dresselhaus ferroelectric CsBiNb2O7 (open access)

Persistent spin helix in Rashba-Dresselhaus ferroelectric CsBiNb2O7

Article reporting that CsBiNb₂O₇, a layered perovskite of Dion-Jacobson type, is a robust ferroelectric with sufficiently strong spin-orbit coupling and spin texture reversible by electric field. The study reveals that its topmost valence band's spin texture is quasi-independent from the momentum, as a result of the low symmetry of its ferroelectric phase. The peculiar spin-polarization pattern in the momentum space may yield the so-called “persistent spin helix,” a specific spin-wave mode which protects the spin from decoherence in the diffusive transport regime, potentially ensuring a very long spin lifetime in this material.
Date: August 19, 2019
Creator: Sławińska, Jagoda; Autieri, Carmine; Barone, Paolo & Picozzi, Silvia
Object Type: Article
System: The UNT Digital Library
Absorption and emission modulation in a MoS2–GaN (0001) heterostructure by interface phonon–exciton coupling (open access)

Absorption and emission modulation in a MoS2–GaN (0001) heterostructure by interface phonon–exciton coupling

Article reporting the change in the transient absorption characteristics of monolayer MoS2 and the modified PL emission characteristics in a monolayer MoS2–GaN (0001) heterostructure due to the coupling of carriers with the phonon modes and the energy exchange at the interface. The results demonstrate the relevance of interface coupling between the semiconductors for the development of optical and electronic applications.
Date: September 26, 2019
Creator: Poudel, Yuba; Sławińska, Jagoda; Gopal, Priya; Seetharaman, Sairaman; Hennighausen, Zachariah; Kar, Swastik et al.
Object Type: Article
System: The UNT Digital Library
Multitask deep-learning-based design of chiral plasmonic metamaterials (open access)

Multitask deep-learning-based design of chiral plasmonic metamaterials

This article presents an end-to-end functional bidirectional deep-learning (DL) model for three-dimensional chiral metamaterial design and optimization. This ML model utilizes multitask joint learning features to recognize, generalize, and explore in detail the nontrivial relationship between the metamaterials’ geometry and their chiroptical response, eliminating the need for auxiliary networks or equivalent approaches to stabilize the physically relevant output. This model efficiently realizes both forward and inverse retrieval tasks with great precision, offering a promising tool for iterative computational design tasks in complex physical systems. Other potential applications include photodetectors, polarization-resolved imaging, and circular dichroism (CD) spectroscopy.
Date: July 1, 2020
Creator: Ashalley, Eric; Acheampong, Kingsley; Besteiro, Lucas V.; Yu, Peng; Neogi, Arup; Govorov, Alexander O. et al.
Object Type: Article
System: The UNT Digital Library
Sub-wavelength lateral detection of tissue-approximating masses using an ultrasonic metamaterial lens (open access)

Sub-wavelength lateral detection of tissue-approximating masses using an ultrasonic metamaterial lens

Article demonstrating a phononic metamaterial lens (ML) for detection of laterally subwavelength object features in tissue-like phantoms beyond the phononic crystal evanescent zone and Fresnel zone of the emitter.
Date: November 24, 2020
Creator: Walker, Ezekiel; Jin, Yuqi; Reyes, Delfino & Neogi, Arup
Object Type: Article
System: The UNT Digital Library
Anisotropic optical properties of single Si2Te3 nanoplates (open access)

Anisotropic optical properties of single Si2Te3 nanoplates

Article reporting a combined experimental and computational study of the optical properties of individual silicon telluride (Si2Te3) nanoplates.
Date: November 5, 2020
Creator: Chen, Jiyang; Bhattarai, Romakanta; Cui, Jingbiao; Shen, Xiao & Hoang, Thang
Object Type: Article
System: The UNT Digital Library
Sub-Diffraction-Limit Imaging System with two Interfacing Hyperbolic Metamaterials (open access)

Sub-Diffraction-Limit Imaging System with two Interfacing Hyperbolic Metamaterials

Article demonstrating that a system of two interfacing hyperbolic metamaterials may be used for direct subwavelength imaging in the visible range.
Date: October 27, 2021
Creator: Bronnikov, Kirill; Arriaga, J.; Krokhin, Arkadii A. & Drachev, Vladimir P.
Object Type: Article
System: The UNT Digital Library
A Miniature Permanent Magnet Assembly with Localized and Uniform Field with an Application to Optical Pumping of Helium (open access)

A Miniature Permanent Magnet Assembly with Localized and Uniform Field with an Application to Optical Pumping of Helium

Article using simulations and experimental measurements to design, build, and test a compact and uniform magnetic field source and then apply it to the optical pumping of atomic helium.
Date: September 24, 2021
Creator: Cameron, Garnet; Cuevas, Jonathan; Pound, Jeffrey Jr. & Shiner, David
Object Type: Article
System: The UNT Digital Library
Connecting Galaxies and Supermassive Black Holes: Meso-scale Simulations of Multiphase Accretion Flows (open access)

Connecting Galaxies and Supermassive Black Holes: Meso-scale Simulations of Multiphase Accretion Flows

Data management plan for the grant, "Connecting Galaxies and Supermassive Black Holes: Meso-scale Simulations of Multiphase Accretion Flows." It proposes to study how gas flows onto the supermassive black holes in massive galaxies and galaxy clusters. They will perform numerical simulations with a nested zoom-in technique, focusing on the mesoscale accretion flows from the Bondi radius to hundreds of Schwarzschild radii. They will predict the mass flux of different phases, as well as their angular momentum and magnetic flux.
Date: 2022-07-01/2025-06-30
Creator: Li, Yuan
Object Type: Text
System: The UNT Digital Library
Grand canonical simulations of electrochemical interfaces in implicit solvation models (open access)

Grand canonical simulations of electrochemical interfaces in implicit solvation models

Article discussing grand canonical simulations based on density-functional theory to study the thermodynamic properties of electrochemical interfaces of metallic electrodes in aqueous environments.
Date: August 31, 2018
Creator: Hörmann, Nicolas; Andreussi, Oliviero & Marzari, Nicola
Object Type: Article
System: The UNT Digital Library
Lattice quantum magnetometry (open access)

Lattice quantum magnetometry

Article presenting the idea of lattice quantum magnetometry, i.e., quantum sensing of magnetic fields by a charged (spinless) particle placed on a finite two-dimensional lattice.
Date: June 24, 2019
Creator: Razzoli, Luca; Ghirardi, Luca; Siloi, Ilaria; Bordone, Paolo & Paris, Matteo G. A.
Object Type: Article
System: The UNT Digital Library
Edge-plasmon assisted electro-optical modulator (open access)

Edge-plasmon assisted electro-optical modulator

Article demonstrates an efficient electro-optical modulation by using an edge-plasmon mode specific for the hybrid plasmonic waveguide.
Date: November 26, 2019
Creator: Drachev, Vladimir P.; Pshenichnyuk, Ivan A.; Nazarikov, Gleb I.; Kosolobov, Sergey S. & Maimistov, Andrei I.
Object Type: Article
System: The UNT Digital Library
AFLOW-QHA3P: Robust and automated method to compute thermodynamic properties of solids (open access)

AFLOW-QHA3P: Robust and automated method to compute thermodynamic properties of solids

Article introducing the quasiharmonic approximation three-phonon method to calculate the thermodynamic properties of both nonmetallic and metallic compounds. This study demonstrates that QHA3P is an ideal framework for the high-throughput prediction of finite-temperature material properties, combining the accuracy of QHA with the computational efficiency of SC-QHA.
Date: July 8, 2019
Creator: Nath, Pinku; Usanmaz, Demet; Hicks, David; Oses, Corey; Fornari, Marco; Buongiorno Nardelli, Marco et al.
Object Type: Article
System: The UNT Digital Library
Role of quantum confinement and interlayer coupling in CrI3-graphene magnetic tunnel junctions (open access)

Role of quantum confinement and interlayer coupling in CrI3-graphene magnetic tunnel junctions

Article presents a combination of first principles and quantum ballistic transport calculations to shed important insights from an atomistic viewpoint on the underlying mechanisms governing spin transport in graphene/ CrI₃ junctions.
Date: May 29, 2020
Creator: Buongiorno Nardelli, Marco; Heath, Jonathan J.; Costa, Marcio & Kuroda, Marcelo A.
Object Type: Article
System: The UNT Digital Library
Unusual Mathematical Approaches Untangle Nervous Dynamics (open access)

Unusual Mathematical Approaches Untangle Nervous Dynamics

Article reports that the massive amount of available neurodata suggests the existence of a mathematical backbone underlying neuronal oscillatory activities. The authors assert that the Monge’s theorem might contribute to our visual ability of depth perception and the brain connectome can be tackled in terms of tunnelling nanotubes.
Date: October 14, 2022
Creator: Tozzi, Arturo & Mariniello, Lucio
Object Type: Article
System: The UNT Digital Library
Evolutionary models of lateralization: Steps toward stigmergy? (open access)

Evolutionary models of lateralization: Steps toward stigmergy?

Article discusses an interesting approach to accounting for brain and behavioral asymmetry based on competition and cooperation in phenotypically asymmetric individuals. The model in question shows, in an almost fully analytical way, that under proper conditions, there exists an unequal number of equilibrium of left-and right-lateralized individuals.
Date: February 2, 2023
Creator: Tonello, Lucio & Vallortigara, Giorgio
Object Type: Article
System: The UNT Digital Library
Exploring thermal properties of nanoscale wide bandgap semiconductors via  ultrafast thermal-emission spectroscopy (open access)

Exploring thermal properties of nanoscale wide bandgap semiconductors via ultrafast thermal-emission spectroscopy

Data management plan for the grant, "Exploring thermal properties of nanoscale wide bandgap semiconductors via ultrafast thermal-emission spectroscopy." In this project, we aim to develop a new thermometrology technique based on ultrafast thermal emission to directly and accurately measure thermal properties of thin-film wide bandgap semiconductors.
Date: 2023-09-30/2025-09-29
Creator: Xiao, Yuzhe
Object Type: Text
System: The UNT Digital Library
Tuning the decay of sound in a viscous metamaterial (open access)

Tuning the decay of sound in a viscous metamaterial

Authors of the article use analytical results for viscous dissipation in phononic crystals to calculate the decay coefficient of a sound wave propagating at low frequencies through a two-dimensional phononic crystal with a viscous fluid background. They claim that the decay coefficient exhibits dependence on the direction of propagation; that is, a homogenized phononic crystal behaves like an anisotropic viscous fluid.
Date: October 10, 2022
Creator: Ibarias, M.; Doporto, J.; Krokhin, Arkadii A. & Arriaga, J.
Object Type: Article
System: The UNT Digital Library
Complexity Synchronization: Information Transmission among Complex Systems (open access)

Complexity Synchronization: Information Transmission among Complex Systems

Data management plan for the grant, "Complexity Synchronization: Information Transmission among Complex Systems."
Date: 2023-09-29/2024-09-28
Creator: Grigolini, Paolo
Object Type: Text
System: The UNT Digital Library
Evaluation of the Vibration Signal during Milling Vertical Thin-Walled Structures from Aerospace Materials (open access)

Evaluation of the Vibration Signal during Milling Vertical Thin-Walled Structures from Aerospace Materials

Article describes how the main functions of thin-walled structures are to reduce the weight of the finished product and to increase the rigidity of the structure. The authors compared the vibration signal for different approaches to machining thin walled-components with vertical walls made of Ti6AI4V titanium alloy and Inconel 625 nickel alloy.
Date: July 14, 2023
Creator: Kurpiel, Szymon; Zagrórski, Krzysztof; Skryzpkowski, Krzysztof & Brostow, Witold, 1934-
Object Type: Article
System: The UNT Digital Library