Plasmonically-powered hot carrier induced modulation of light emission in a two-dimensional GaAs semiconductor quantum well (open access)

Plasmonically-powered hot carrier induced modulation of light emission in a two-dimensional GaAs semiconductor quantum well

Article describes an experiment in which a hot-electron-enabled route to controlling light with dissipative loss compensation in semiconductor quantum light emitters has been realized for tunable quantum optoelectronic devices via a two-species plasmon system.
Date: December 10, 2018
Creator: Ashalley, Eric; Gryczynski, Karol; Wang, Zhiming; Salamo, Gregory & Neogi, Arup
System: The UNT Digital Library
Thermal instability and multiphase gas in the simulated interstellar medium with conduction, viscosity, and magnetic fields (open access)

Thermal instability and multiphase gas in the simulated interstellar medium with conduction, viscosity, and magnetic fields

This article uses 2D simulations to investigate thermal instability under the influence of various initial conditions and physical processes.
Date: June 7, 2021
Creator: Jennings, R. Michael & Li, Yuan
System: The UNT Digital Library
Electrostatic equilibria of non-neutral plasmas confined in a Penning trap with axially varying magnetic field (open access)

Electrostatic equilibria of non-neutral plasmas confined in a Penning trap with axially varying magnetic field

This article describes a procedure for computing the electrostatic equilibria of non-neutral plasmas in a Penning trap with a nonuniform magnetic field by solving Poisson's equation using an iterative method. Plasma equilibria in a model Penning trap with high and low field regions are computed. The plasma is assumed to follow the Boltzmann density distribution along magnetic field lines.
Date: May 21, 2019
Creator: Lane, Ryan A. & Ordonez, Carlos A.
System: The UNT Digital Library

Artificially structured boundary plasma trap

This article presents a computer simulation of single-species non-neutral plasma confinement using an artificially structured boundary. The results support the prospect of developing plasma space-charge based confinement, with an unmagnetized plasma of one species of charged particles confined by an electric field produced by an edge-confined plasma of a second species of charged particles.
Date: September 20, 2019
Creator: Hedlof, R. M. & Ordonez, Carlos A.
System: The UNT Digital Library
ALMA Observations of Quasar Host Galaxies at z ≃ 4.8 (open access)

ALMA Observations of Quasar Host Galaxies at z ≃ 4.8

Article presents ALMA Band 7 data of the [C ıı] 𝜆157.74 𝜇m emission line and underlying far-IR (FIR) continuum for 12 luminous quasars at 𝓏 ≃ 4.8 powered by fast-growing supermassive black holes (SMBHs).
Date: May 27, 2020
Creator: Shemmer, Ohad; Nguyen, Nathen H.; Lira, Paulina; Trakhtenbrot, Benny; Netzer, Hagai; Cicone, Claudia et al.
System: The UNT Digital Library
Engineered nonlinear materials using gold nanoantenna array (open access)

Engineered nonlinear materials using gold nanoantenna array

This article describes the use of a gold nanoantenna array to enhance both the nonlinear refractive index and two-photon absorption (2PA) of the organic dye 4,4'-bis(diphenylamino)stilbene (BDPAS), which is known as a dye with relatively large 2PA.
Date: August 21, 2017
Creator: Drachev, Vladimir P.; Kildishev, Alexander V.; Borneman, Joshua D.; Chen, Kuo-Ping; Shalaev, Vladimir; Yamnitskiy, Konstantin et al.
System: The UNT Digital Library
Growth of Highly-Ordered Metal Nanoparticle Arrays in the Dimpled Pores of an Anodic Aluminum Oxide Template (open access)

Growth of Highly-Ordered Metal Nanoparticle Arrays in the Dimpled Pores of an Anodic Aluminum Oxide Template

Article presents a reliable, scalable, and inexpensive technology for the fabrication of ordered arrays of metal nanoparticles with large areal coverage on various substrates. Using a simple model, the experimental results were interpreted and supported by numerical estimations.
Date: November 8, 2022
Creator: Farmer, Gavin; Abraham, James; Littler, Chris; Syllaios, A. J. & Philipose, Usha
System: The UNT Digital Library
Simulation of an electrostatic quadrupole quadruplet focusing lens system for MeV multi-ion micro-beam (open access)

Simulation of an electrostatic quadrupole quadruplet focusing lens system for MeV multi-ion micro-beam

Article presents the simulations of an electrostatic quadrupole quadruplet (EQQ) lens system that will be used in a new sub-micron multi-ion beam for radiobiological studies.
Date: October 2, 2019
Creator: Glass, Gary A.; Chirayath, V. A.; Arya, H.; Jin, M.; Weiss, A. H. & Chi, Y.
System: The UNT Digital Library
Artificially structured boundary for confinement of effectively unmagnetized cryogenic antimatter plasmas (open access)

Artificially structured boundary for confinement of effectively unmagnetized cryogenic antimatter plasmas

The article is from conference proceedings that discuss an artificially structured boundary (ABS) considered to consist of a spatially periodic arrangement of electrostatically plugged magnetic cusps. As envisioned, a non-neutral positron plasma could be confined by an ASB along its edge, and the space charge of the positron plasma would serve to confine an antiproton plasma. If the conditions of the two-species plasma are suitable, production of antihydrogen via three-body recombination for antimatter gravity studies may be possible.
Date: January 23, 2018
Creator: Hedlof, R. M. & Ordonez, Carlos A.
System: The UNT Digital Library
Giant spin Hall effect in two-dimensional monochalcogenides (open access)

Giant spin Hall effect in two-dimensional monochalcogenides

This article, using calculations from first principles, reveals for the first time giant intrinsic spin Hall conductivities (SHC) in these materials. In particular, the article shows that the SHC resonances can be easily tuned by combination of strain and doping and, in some cases, strain can be used to induce semiconductor to metal transition that makes a giant spin Hall effect possible even in absence of doping.
Date: October 30, 2018
Creator: Sławińska, Jagoda; Cerasoli, Frank T.; Wang, Haihang; Postorino, Sara; Supka, Andrew; Curtarolo, Stefano et al.
System: The UNT Digital Library
Polarization in electrostatics and circuits: Computing and visualizing surface charge distributions (open access)

Polarization in electrostatics and circuits: Computing and visualizing surface charge distributions

Article describing an algorithm or computing the detailed surface charge distributions in equilibrium electrostatic situations and in steady-state DC circuits, and discuss the results of the computations of surface charge distributions for several systems.
Date: December 14, 2018
Creator: Chabay, Ruth & Sherwood, Bruce
System: The UNT Digital Library
Discovery of the first heavily obscured QSO candidate at z > 6 in a close galaxy pair (open access)

Discovery of the first heavily obscured QSO candidate at z > 6 in a close galaxy pair

This article reports the Chandra discovery of the first heavily obscured QSO candidate in the early universe, hosted by a close (≈5 kpc) galaxy pair at z = 6.515.
Date: May 17, 2022
Creator: Vito, F.; Brandt, William Nielsen; Bauer, Franz E.; Gilli, Roberto; Luo, B.; Zamorani, G. et al.
System: The UNT Digital Library
Deep Minima in the Triply Differential Cross Section for Ionization of Atomic Hydrogen by Electron and Positron Impact (open access)

Deep Minima in the Triply Differential Cross Section for Ionization of Atomic Hydrogen by Electron and Positron Impact

Article investigating ionization of atomic hydrogen by electron- and positron-impact. This article belongs to the Special Issue: Interactions of Positrons with Matter and Radiation.
Date: May 29, 2020
Creator: DeMars, C. M.; Ward, S. J.; Colgan, J.; Amami, S. & Madison, D. H.
System: The UNT Digital Library
Deep Minimum and a Vortex for Positronium Formation in Low-Energy Positron-Helium Collisions (open access)

Deep Minimum and a Vortex for Positronium Formation in Low-Energy Positron-Helium Collisions

This article finds a zero in the positronium formation scattering amplitude and a deep minimum in the logarithm of the corresponding differential cross section for positron–helium collisions for an energy just above the positronium formation threshold. Results show that there is a valley in the logarithm of the positronium formation differential cross section that includes the deep minimum and also a minimum in the forward direction.
Date: August 6, 2021
Creator: Alrowaily, Albandari W.; Quintanilla, Sandra J. & Van Reeth, Peter
System: The UNT Digital Library

Chandra and Magellan/FIRE follow-up observations of PSO167–13: An X-ray weak QSO at z = 6.515

This article presents the results of follow-up observations of the z = 6.515 radio-quiet QSO PSO167–13, which is interacting with a close companion galaxy with the goal to confirm the existence of the X-ray source and to investigate the rest-frame UV properties of the QSO. The authors observed the PSO167–13 system with Chandra/ACIS-S (177 ks) and obtained new spectroscopic observations (7.2 h) with Magellan/FIRE.
Date: May 27, 2021
Creator: Vito, F.; Brandt, William Nielsen; Ricci, F.; Congui, E.; Connor, T.; Bañados, E. et al.
System: The UNT Digital Library
An X-ray fading, UV brightening QSO at z ≈ 6 (open access)

An X-ray fading, UV brightening QSO at z ≈ 6

Article presents quasi-simultaneous X-ray and rest-frame UV observations of quasi-stellar object (QSO) z = 6.025 QSO J1641+3755.
Date: July 26, 2022
Creator: Vito, F.; Mignoli, M.; Gilli, R.; Brandt, William Nielsen; Shemmer, Ohad; Bauer, Franz E. et al.
System: The UNT Digital Library
Temporal complexity measure of reaction time series: Operational versus event time (open access)

Temporal complexity measure of reaction time series: Operational versus event time

Article describes how detrended fluctuation analysis (DFA) is a well-established method to evaluate scaling indices of time series, which categorize the dynamics of complex systems. The authors propose treating each reaction time as a duration time that changes the representation from operational (trial number) time n to event (temporal) time t, or X(t).
Date: May 23, 2023
Creator: Mahmoodi, Korosh; Kerick, Scott E.; Grigolini, Paolo; Franaszczuk, Pitor J. & West, Bruce J.
System: The UNT Digital Library
Gemini Near Infrared Spectrograph–Distant Quasar Survey: Prescriptions for Calibrating UV-based Estimates of Supermassive Black Hole Masses in High-redshift Quasars (open access)

Gemini Near Infrared Spectrograph–Distant Quasar Survey: Prescriptions for Calibrating UV-based Estimates of Supermassive Black Hole Masses in High-redshift Quasars

Article describes how the most reliable single-epoch supermassive black hole mass (MBH) estimates in quasars are obtained by using the velocity widths of low-ionization emission lines, typically the Hβλ4861 line. The authors find that utilizing both emission lines, where available, reduces the scatter of UV-based MBH estimates by ∼15% when compared to previous studies.
Date: June 13, 2023
Creator: Dix, Cooper; Matthews, Brandon; Shemmer, Ohad; Brotherton, Michael S.; Myers, Adam D.; Andruchow, I. et al.
System: The UNT Digital Library
Uncoupling system and environment simulation cells for fast-scaling modeling of complex continuum embeddings (open access)

Uncoupling system and environment simulation cells for fast-scaling modeling of complex continuum embeddings

Article describes how continuum solvation models are becoming increasingly relevant in condensed matter simulations, allowing to characterize materials interfaces in the presence of wet electrified environments at a reduced computational cost with respect to all atomistic simulations. However, some challenges with the implementation of these models in plane-wave simulation packages still persists, and to address these challenges, the authors present the implementation of a double-cell formalism, in which the simulation cell used for the continuum environment is uncoupled from the one used for the electronic-structure simulation of the quantum-mechanical system.
Date: August 1, 2023
Creator: Medrano, G.; Bainglass, E. & Andreussi, O.
System: The UNT Digital Library
Optical Pump Terahertz Probe (OPTP) and Time Resolved Terahertz Spectroscopy (TRTS) of emerging solar materials Editor’s Pick (open access)

Optical Pump Terahertz Probe (OPTP) and Time Resolved Terahertz Spectroscopy (TRTS) of emerging solar materials Editor’s Pick

Article describes how photoconductivity is the crucial benchmark to assess the potential of any emerging material for future solar applications. This tutorial aims to familiarize the reader with the main THz techniques used to explore emerging materials.
Date: July 19, 2023
Creator: Neu, Jens
System: The UNT Digital Library
Long-range nonspreading propagation of sound beam through periodic layered structure (open access)

Long-range nonspreading propagation of sound beam through periodic layered structure

Article analyzing dispersion of sound in a solid-fluid layered structure and found a flex point on the isofrequency curve where D vanishes for given direction of propagation and frequency. Nonspreading propagation is experimentally observed in a water steel lattice of 75 periods (~1 meter long) and occurs in the regime of anomalous dispersion and strong acoustic anisotropy when the effective mass along periodicity is close to zero. Under these conditions the incoming beam experiences negative refraction of phase velocity leading to backward wave propagation. The observed effect is explained using a complete set of dynamical equations and our effective medium theory.
Date: September 2, 2020
Creator: Zubov, Yurii; Djafari-Rouhani, Bahram; Jin, Yuqi; Sofield, Mathew; Walker, Ezekiel; Neogi, Arup et al.
System: The UNT Digital Library
Advanced modeling of materials with PAOFLOW 2.0: New features and software design (open access)

Advanced modeling of materials with PAOFLOW 2.0: New features and software design

This article describes the recent re-design of the code and the new features and improvements in performance of PAOFLOW, a software tool that constructs tight-binding Hamiltonians from self-consistent electronic wavefunctions by projecting onto a set of atomic orbitals.
Date: September 2, 2021
Creator: Cesaroli, Frank T.; Supka, Andrew; Jayaraj, Anooja; Costa, Marcio; Siloi, Ilaria; Sławińska, Jagoda et al.
System: The UNT Digital Library
Topological View of Flows Inside the BOLD Spontaneous Activity of the Human Brain (open access)

Topological View of Flows Inside the BOLD Spontaneous Activity of the Human Brain

Article describes study which found that persistent, recurring blood oxygen level dependent (BOLD) signals in triangulated rs-fMRI videoframes display previously undetected topological findings, i.e., vortex structures that cover brain activated regions.
Date: April 22, 2020
Creator: Don, Arjuna P. H.; Peters, James F.; Ramanna, Sheela & Tozzi, Arturo
System: The UNT Digital Library
Self-Organized Temporal Criticality: Bottom-Up Resilience versus Top-Down Vulnerability (open access)

Self-Organized Temporal Criticality: Bottom-Up Resilience versus Top-Down Vulnerability

This article proposes a social model of spontaneous self-organization generating criticality and resilience, called Self-Organized Temporal Criticality (SOTC).
Date: March 26, 2018
Creator: Mahmoodi, Korosh; West, Bruce J. & Grigolini, Paolo
System: The UNT Digital Library