Open Access. Powered by Scholars. Published by Universities.®

Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

Iowa State University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 31 - 60 of 2631

Full-Text Articles in Physics

Topological States In A15 Superconductors, Minsung Kim, Cai-Zhuang Wang, Kai-Ming Ho Jun 2019

Topological States In A15 Superconductors, Minsung Kim, Cai-Zhuang Wang, Kai-Ming Ho

Ames Laboratory Accepted Manuscripts

Superconductors with the A15 structure are prototypical type-II s-wave superconductors which have generated considerable interest in early superconducting material history. However, the topological nature of the electronic structure remains unnoticed so far. Here, using first-principles band structure calculations based on density-functional theory, we show that the A15 superconductors (Ta3Sb, Ta3Sn, and Ta3Pb) have nontrivial band topology in the bulk electronic band structures, leading to the formation of topological surface states near the Fermi energy. Due to the bulk superconductivity, the proximity effect in the topological surface states would induce topological superconductivity even without heterostructure of a topological insulator and an ...


Magnetic Fluctuations In The Itinerant Ferromagnet Lacrge3 Studied By 139la Nmr, K. Rana, H. Kotegawa, R. R. Ullah, J. S. Harvey, Sergey L. Bud’Ko, Paul C. Canfield, H. Tou, V. Taufour, Yuji Furukawa Jun 2019

Magnetic Fluctuations In The Itinerant Ferromagnet Lacrge3 Studied By 139la Nmr, K. Rana, H. Kotegawa, R. R. Ullah, J. S. Harvey, Sergey L. Bud’Ko, Paul C. Canfield, H. Tou, V. Taufour, Yuji Furukawa

Ames Laboratory Accepted Manuscripts

LaCrGe3 is an itinerant ferromagnet with a Curie temperature of T C = 85 K and exhibits an avoided ferromagnetic quantum critical point under pressure through a modulated antiferromagnetic phase as well as tricritical wing structure in its temperature-pressure-magnetic field ( T – p – H) phase diagram. In order to understand the static and dynamical magnetic properties of LaCrGe3 , we carried out 139 La nuclear magnetic resonance (NMR) measurements. Based on the analysis of NMR data, using the self-consistent-renormalization (SCR) theory, the spin fluctuations in the paramagnetic state are revealed to be isotropic ferromagnetic and three dimensional (3D) in nature. Furthermore, the system ...


Crystal Growth And Magnetic Structure Of Mnbi2 Te 4, J.-Q. Yan, Q. Zhang, T. Heitmann, Zengle Huang, K. Y. Chen, J.-G. Cheng, Weida Wu, David Vaknin, B. C. Sales, Robert J. Mcqueeney Jun 2019

Crystal Growth And Magnetic Structure Of Mnbi2 Te 4, J.-Q. Yan, Q. Zhang, T. Heitmann, Zengle Huang, K. Y. Chen, J.-G. Cheng, Weida Wu, David Vaknin, B. C. Sales, Robert J. Mcqueeney

Ames Laboratory Accepted Manuscripts

Millimeter-sized MnBi2Te4 single crystals are grown out of a Bi-Te flux and characterized using magnetic, transport, scanning tunneling microscopy, and spectroscopy measurements. The magnetic structure of MnBi2Te4 below TN is determined by powder and single-crystal neutron diffraction measurements. Below TN = 24 K, Mn2+ moments order ferromagnetically in the ab plane but antiferromagnetically along the crystallographic c axis. The ordered moment is 4.04(13)μB/Mn at 10 K and aligned along the crystallographic c axis in an A-type antiferromagnetic order. Below TN, the electrical resistivity drops upon cooling or when going across the metamagnetic transition in increasing magnetic fields ...


Thermodynamic Stabilities Of Perfect And Vacancy-Defected Li2 Tio3 (001) Surfaces From First-Principles Analyses, Yan Jiang, Yanli Shi, Xiaogang Xiang, Jianqi Qi, Yong Han, Zhijun Liao, Tiecheng Lu May 2019

Thermodynamic Stabilities Of Perfect And Vacancy-Defected Li2 Tio3 (001) Surfaces From First-Principles Analyses, Yan Jiang, Yanli Shi, Xiaogang Xiang, Jianqi Qi, Yong Han, Zhijun Liao, Tiecheng Lu

Ames Laboratory Accepted Manuscripts

Lithium titanate (Li2TiO3) is an attractive ceramic material for various industrial applications, particularly as one of the most promising breeder blanket materials in future nuclear-fusion reactors. Previously reported studies mainly focus on sintered polycrystalline samples of Li2TiO3. Surface structure of the single-crystal form is rarely reported, although the information of surface structures and stabilities can be critical for further understanding the surface-associated processes. In this work, we perform extensive first-principles density-functional-theory (DFT) calculations to obtain the surface energies of Li2TiO3 (001) with different surface terminations. For four perfect (defect-free) Li-, O-, or LiTi-terminated (001) surfaces, Li- or O-terminated (001) surfaces ...


Magnetic-Field Effects On The Fragile Antiferromagnetism In Ybbipt, Benjamin G. Ueland, Andreas Kreyssig, E. D. Mun, J. W. Lynn, L. W. Harriger, D. K. Pratt, K. Prokeš, Z. Hüsges, R. Toft-Petersen, S. Sauerbrei, Scott M. Saunders, Yuji Furukawa, Sergey L. Bud’Ko, Robert J. Mcqueeney, Paul C. Canfield, Alan I. Goldman May 2019

Magnetic-Field Effects On The Fragile Antiferromagnetism In Ybbipt, Benjamin G. Ueland, Andreas Kreyssig, E. D. Mun, J. W. Lynn, L. W. Harriger, D. K. Pratt, K. Prokeš, Z. Hüsges, R. Toft-Petersen, S. Sauerbrei, Scott M. Saunders, Yuji Furukawa, Sergey L. Bud’Ko, Robert J. Mcqueeney, Paul C. Canfield, Alan I. Goldman

Ames Laboratory Accepted Manuscripts

We present neutron-diffraction data for the cubic-heavy-fermion YbBiPt that show broad magnetic diffraction peaks due to the fragile short-range antiferromagnetic (AFM) order persist under an applied magnetic-field H. Our results for H perpendicular to[(1) over bar 1 0] and a temperature of T = 0.14(1) K show that the (1/2,1/2,3/2) magnetic diffraction peak can be described by the same two-peak line shape found for mu H-0 = 0T below the Neel temperature of T-N = 0.4 K. Both components of the peak exist for mu H-0 less than or similar to 1.4 T ...


Characteristics Of Sulfur Atoms Adsorbed On Ag(100), Ag(110), And Ag(111) As Probed With Scanning Tunneling Microscopy: Experiment And Theory, Peter M. Spurgeon, Da-Jiang Liu, Holly Walen, Junepyo Oh, Hyun Jin Yang, Yousoo Kim, Patricia A. Thiel May 2019

Characteristics Of Sulfur Atoms Adsorbed On Ag(100), Ag(110), And Ag(111) As Probed With Scanning Tunneling Microscopy: Experiment And Theory, Peter M. Spurgeon, Da-Jiang Liu, Holly Walen, Junepyo Oh, Hyun Jin Yang, Yousoo Kim, Patricia A. Thiel

Chemistry Publications

In this paper, we report that S atoms on Ag(100) and Ag(110) exhibit a distinctive range of appearances in scanning tunneling microscopy (STM) images, depending on the sample bias voltage, VS. Progressing from negative to positive VS, the atomic shape can be described as a round protrusion surrounded by a dark halo (sombrero) in which the central protrusion shrinks, leaving only a round depression. This progression resembles that reported previously for S atoms on Cu(100). We test whether DFT can reproduce these shapes and the transition between them, using a modified version of the Lang–Tersoff–Hamann ...


Measurement Of Charm And Bottom Production From Semileptonic Hadron Decays In P + P Collisions At √S = 200 Gev, C. Aidala, Nicole J. Apadula, John C. Hill, Nels J. Hotvedt, John G. Lajoie, Alexandre Lebedev, S. H. Lee, Craig Ogilvie, Milap R. Patel, Joshua Perry, Timothy T. Rinn, Marzia Rosati, Jonathan C. Runchey, Abhisek Sen, M. Shimomura, Arbin Timilsina, Yunxiao Zhai, Et Al., Phenix Collaboration May 2019

Measurement Of Charm And Bottom Production From Semileptonic Hadron Decays In P + P Collisions At √S = 200 Gev, C. Aidala, Nicole J. Apadula, John C. Hill, Nels J. Hotvedt, John G. Lajoie, Alexandre Lebedev, S. H. Lee, Craig Ogilvie, Milap R. Patel, Joshua Perry, Timothy T. Rinn, Marzia Rosati, Jonathan C. Runchey, Abhisek Sen, M. Shimomura, Arbin Timilsina, Yunxiao Zhai, Et Al., Phenix Collaboration

Physics and Astronomy Publications

Measurements of the differential production of electrons from open-heavy-flavor hadrons with charm- and bottom-quark content in p+p collisions at √s=200  GeV are presented. The measurements proceed through displaced-vertex analyses of electron tracks from the semileptonic decay of charm and bottom hadrons using the PHENIX silicon-vertex detector. The relative contribution of electrons from bottom decays to inclusive heavy-flavor-electron production is found to be consistent with fixed-order-plus-next-to-leading-log perturbative-QCD calculations within experimental and theoretical uncertainties. These new measurements in p+p collisions provide a precision baseline for comparable forthcoming measurements in A+A collisions.


Measurement Of Two-Particle Correlations With Respect To Second- And Third-Order Event Planes In Au + Au Collisions At √Snn=200 Gev, A. Adare, John C. Hill, Nels J. Hotvedt, Todd Kempel, John G. Lajoie, Alexandre Lebedev, S. H. Lee, Craig Ogilvie, Milap R. Patel, H. Pei, Timothy T. Rinn, Marzia Rosati, Jonathan C. Runchey, Alexey Yu. Semenov, M. Shimomura, Carla Vale, Feng Wei, Et Al., Phenix Collaboration May 2019

Measurement Of Two-Particle Correlations With Respect To Second- And Third-Order Event Planes In Au + Au Collisions At √Snn=200 Gev, A. Adare, John C. Hill, Nels J. Hotvedt, Todd Kempel, John G. Lajoie, Alexandre Lebedev, S. H. Lee, Craig Ogilvie, Milap R. Patel, H. Pei, Timothy T. Rinn, Marzia Rosati, Jonathan C. Runchey, Alexey Yu. Semenov, M. Shimomura, Carla Vale, Feng Wei, Et Al., Phenix Collaboration

Physics and Astronomy Publications

We present measurements of azimuthal correlations of charged hadron pairs in root s(NN) = 200 GeV Au + Au collisions for the trigger and associated particle transverse-momentum ranges of 1 < p(T)(t) < 10 GeV/c and 0.5 < p(T)(a) < 10 GeV/c. After subtraction of an underlying event using a model that includes higher-order azimuthal anisotropy v(2), v(3,) and v(4), the away-side yield of the highest trigger-p(T)(p(T)(t) > 4 GeV/c) correlations is suppressed compared with that of correlations measured in p + p collisions. At the lowest associated particle p(T)(0.5 < p(T)(a) < 1 GeV/c), the away-side shape and yield are modified relative to those in p + p collisions. These observations are consistent with the scenario of radiative-jet energy loss. For the low-p(T) trigger correlations (2 < p(T)(t) < 4 GeV/c), a finite away-side yield exists and we explore the dependence of the shape of the away-side within the context of an underlying-event model. Correlations are also studied differentially versus event-plane angle Psi(2) and Psi(3). The angular correlations show an asymmetry when selecting the sign of the difference between the trigger-particle azimuthal angle and the Psi(2) event plane. This asymmetry and the measured suppression of the pair yield out-of-plane is consistent with a path-length-dependent energy loss. No Psi(3) dependence can be resolved within experimental uncertainties.


Observation Of Η-Al41sm5 Reveals Motif-Aware Structural Evolution In Al-Sm Alloys, Zhuo Ye, F. Meng, Feng Zhang, Yang Sun, L. Yang, S. H. Zhou, Ralph E. Napolitano, Mikhail I. Mendelev, Ryan T. Ott, Matthew J. Kramer, Cai-Zhuang Wang, Kai-Ming Ho Apr 2019

Observation Of Η-Al41sm5 Reveals Motif-Aware Structural Evolution In Al-Sm Alloys, Zhuo Ye, F. Meng, Feng Zhang, Yang Sun, L. Yang, S. H. Zhou, Ralph E. Napolitano, Mikhail I. Mendelev, Ryan T. Ott, Matthew J. Kramer, Cai-Zhuang Wang, Kai-Ming Ho

Materials Science and Engineering Publications

Using an effective genetic algorithm, we uncover the structure of a metastable Al41Sm5 phase that supplements its family sharing similar short-range orders. The phase evolves upon heating an amorphous Al-9.7 at.% Sm ribbon, produced by melt-spinning. The dynamical phase selection is discussed with respect to the structural connections between the short-range packing motifs in the amorphous precursor and those observed in the selected phases. The phase elucidated here is one of several newly discovered large-unit-cell phases found to form during devitrification from the glass in this binary system, further illustrating the power and efficiency of our approach, the important ...


Anisotropy Induced Vortex Lattice Rearrangement In Cakfe4as4, Rustem Khasanov, William R. Meier, Sergey L. Bud’Ko, Hubertus Luetkens, Paul C. Canfield, Alex Amato Apr 2019

Anisotropy Induced Vortex Lattice Rearrangement In Cakfe4as4, Rustem Khasanov, William R. Meier, Sergey L. Bud’Ko, Hubertus Luetkens, Paul C. Canfield, Alex Amato

Ames Laboratory Accepted Manuscripts

The magnetic penetration depth anisotropy gamma(lambda) = lambda(c)/lambda(ab) (lambda(ab) and lambda(c) are the in-plane and the out-of-plane components of the magnetic penetration depth) in a CaKFe4As4 single crystal sample (the critical temperature T-c similar or equal to 35 K) was studied by means of muon-spin rotation (mu SR). gamma(lambda) is almost temperature independent for T less than or similar to 20 K (gamma(lambda) similar or equal to 1.9) and it reaches similar or equal to 3.0 by approaching T-c. The change of gamma(lambda) induces the corresponding rearrangement of the flux ...


Magnetocaloric Effect Of Gadolinium In High Magnetic Fields, T. Gottschall, M. D. Kuz’Min, K. P. Skokov, Y. Skourski, M. Fries, O. Gutfleisch, M. Ghorbani Zavareh, Deborah L. Schlagel, Yaroslav Mudryk, Vitalij K. Pecharsky, J. Wosnitza Apr 2019

Magnetocaloric Effect Of Gadolinium In High Magnetic Fields, T. Gottschall, M. D. Kuz’Min, K. P. Skokov, Y. Skourski, M. Fries, O. Gutfleisch, M. Ghorbani Zavareh, Deborah L. Schlagel, Yaroslav Mudryk, Vitalij K. Pecharsky, J. Wosnitza

Ames Laboratory Accepted Manuscripts

The magnetocaloric effect of gadolinium has been measured directly in pulsed magnetic fields up to 62 T. The maximum observed adiabatic temperature change is Delta T-ad = 60.5 K, the initial temperature T-0 being just above 300 K. The field dependence of Delta T-ad is found to follow the usual H-2/3 law, with a small correction in H-4/3. However, as H is increased, a radical change is observed in the dependence of Delta T-ad on T-0, at H = const. The familiar caret-shaped peak situated at T-0 = T-C becomes distinctly asymmetric, its high-temperature slope becoming more gentle and evolving ...


Fragility Of Fermi Arcs In Dirac Semimetals, Yun Wu, Na Hyun Jo, Lin-Lin Wang, Connor A. Schmidt, Kathryn M. Neilson, Benjamin Schrunk, Przemyslaw Swatek, Andrew Eaton, Sergey L. Bud’Ko, Paul C. Canfield, Adam Kaminski Apr 2019

Fragility Of Fermi Arcs In Dirac Semimetals, Yun Wu, Na Hyun Jo, Lin-Lin Wang, Connor A. Schmidt, Kathryn M. Neilson, Benjamin Schrunk, Przemyslaw Swatek, Andrew Eaton, Sergey L. Bud’Ko, Paul C. Canfield, Adam Kaminski

Ames Laboratory Accepted Manuscripts

We use tunable, vacuum ultraviolet laser based angle-resolved photoemission spectroscopy and density functional theory (DFT) calculations to study the electronic properties of Dirac semimetal candidate cubic PtBi 2 . In addition to bulk electronic states we also find surface states in PtBi 2 , which is expected as PtBi 2 was theoretically predicated to be a candidate Dirac semimetal. The surface states are also well reproduced from DFT band calculations. Interestingly, the topological surface states form Fermi contours rather than double Fermi arcs that were observed in Na 3 Bi . The surface bands forming the Fermi contours merge with bulk bands in ...


Pressure-Temperature Phase Diagram Of The Eurbfe4as4 Superconductor, Li Xiang, Sergey L. Bud’Ko, Jin-Ke Bao, Duck Young Chung, Mercouri G. Kanatzidis, Paul C. Canfield Apr 2019

Pressure-Temperature Phase Diagram Of The Eurbfe4as4 Superconductor, Li Xiang, Sergey L. Bud’Ko, Jin-Ke Bao, Duck Young Chung, Mercouri G. Kanatzidis, Paul C. Canfield

Ames Laboratory Accepted Manuscripts

The pressure dependencies of the magnetic and superconducting transitions, as well as that of the superconducting upper critical field, are reported for single crystalline EuRbFe 4 As 4 . Resistance measurements were performed under hydrostatic pressures up to 6.21 GPa and in magnetic fields up to 9 T. Zero-field-cooled magnetization measurements were performed under hydrostatic pressures up to 1.24 GPa under 20 mT applied field. Superconducting transition temperature, T c , up to 6.21 GPa and magnetic transition temperature, T M , up to 1.24 GPa were obtained and a pressure-temperature phase diagram was constructed. Our results show that ...


Intelligent Metasurfaces With Continuously Tunable Local Surface Impedance For Multiple Reconfigurable Functions, Fu Liu, Odysseas Tsilipakos, Alexandros Pitilakis, Anna C. Tasolamprou, Mohammad Sajjad Mirmoosa, Nikolaos V. Kantartzis, Do-Hoon Kwon, Maria Kafesaki, Costas M. Soukoulis, Sergei A. Tretyakov Apr 2019

Intelligent Metasurfaces With Continuously Tunable Local Surface Impedance For Multiple Reconfigurable Functions, Fu Liu, Odysseas Tsilipakos, Alexandros Pitilakis, Anna C. Tasolamprou, Mohammad Sajjad Mirmoosa, Nikolaos V. Kantartzis, Do-Hoon Kwon, Maria Kafesaki, Costas M. Soukoulis, Sergei A. Tretyakov

Ames Laboratory Accepted Manuscripts

Electromagnetic metasurfaces can be characterized as intelligent if they are able to perform multiple tunable functions, with the desired response being controlled by a computer influencing the individual electromagnetic properties of each metasurface inclusion. In this paper, we present an example of an intelligent metasurface that operates in the reflection mode in the microwave frequency range. We numerically show that, without changing the main body of the metasurface, we can achieve tunable perfect absorption and tunable anomalous reflection. The tunability features can be implemented using mixed-signal integrated circuits (ICs), which can independently vary both the resistance and reactance, offering complete ...


Equation Of State Of Boron Nitride Combining Computation, Modeling, And Experiment, Shuai Zhang, Amy Lazicki, Burkhard Militzer, Lin H. Yang, Kyle Caspersen, Jim A. Gaffney, Markus W. Däne, John E. Pask, Walter R. Johnson, Abhiraj Sharma, Phanish Suryanarayana, Duane D. Johnson, Andrey V. Smirnov, Philip A. Sterne, David Erskine, Richard A. London, Federica Coppari, Damian Swift, Joseph Nilsen, Art J. Nelson, Heather D. Whitley Apr 2019

Equation Of State Of Boron Nitride Combining Computation, Modeling, And Experiment, Shuai Zhang, Amy Lazicki, Burkhard Militzer, Lin H. Yang, Kyle Caspersen, Jim A. Gaffney, Markus W. Däne, John E. Pask, Walter R. Johnson, Abhiraj Sharma, Phanish Suryanarayana, Duane D. Johnson, Andrey V. Smirnov, Philip A. Sterne, David Erskine, Richard A. London, Federica Coppari, Damian Swift, Joseph Nilsen, Art J. Nelson, Heather D. Whitley

Ames Laboratory Accepted Manuscripts

The equation of state (EOS) of materials at warm dense conditions poses significant challenges to both theory and experiment. We report a combined computational, modeling, and experimental investigation leveraging new theoretical and experimental capabilities to investigate warm-dense boron nitride (BN). The simulation methodologies include path integral Monte Carlo (PIMC), several density functional theory (DFT) molecular dynamics methods [plane-wave pseudopotential, Fermi operator expansion (FOE), and spectral quadrature (SQ)], activity expansion (actex), and all-electron Green's function Korringa-Kohn-Rostoker (mecca), and compute the pressure and internal energy of BN over a broad range of densities and temperatures. Our experiments were conducted at the ...


Measurements Of Μμ Pairs From Open Heavy Flavor And Drell-Yan In P + P Collisions At √S = 200 Gev, C. Aidala, Nicole J. Apadula, John C. Hill, Nels J. Hotvedt, John G. Lajoie, Alexandre Lebedev, S. H. Lee, Craig Ogilvie, Milap R. Patel, Joshua Perry, Timothy T. Rinn, Marzia Rosati, Jonathan C. Runchey, Abhisek Sen, M. Shimomura, Arbin Timilsina, Et Al., Phenix Collaboration Apr 2019

Measurements Of Μμ Pairs From Open Heavy Flavor And Drell-Yan In P + P Collisions At √S = 200 Gev, C. Aidala, Nicole J. Apadula, John C. Hill, Nels J. Hotvedt, John G. Lajoie, Alexandre Lebedev, S. H. Lee, Craig Ogilvie, Milap R. Patel, Joshua Perry, Timothy T. Rinn, Marzia Rosati, Jonathan C. Runchey, Abhisek Sen, M. Shimomura, Arbin Timilsina, Et Al., Phenix Collaboration

Physics and Astronomy Publications

PHENIX reports differential cross sections of mu mu pairs from semileptonic heavy-flavor decays and the Drell-Yan production mechanism measured in p + p collisions at root s = 200 GeV at forward and backward rapidity (1.2 < vertical bar eta vertical bar < 2.2). The mu mu pairs from c (c) over bar, b (b) over bar, and Drell-Yan are separated using a template fit to unlike- and like-sign muon pair spectra in mass and p(T). The azimuthal opening angle correlation between the muons from c (c ) over bar and b (b) over bar decays and the pair-p(T) distributions are compared to distributions generated using PYTHIA and POWHEG models, which both include next-to-leading order processes. The measured distributions for pairs from a are consistent with PYTHIA calculations. The c (c) over bar data present narrower azimuthal correlations and softer p(T) distributions compared to distributions generated from POWHEG. The b (b ) over bar data are well described by both models. The extrapolated total cross section for bottom production is 3.75 +/- 0.24(stat) +/-(0.35)(0.50) (syst) +/- 0.45(global) [mu b], which is consistent with previous measurements at the Relativistic Heavy Ion Collider in the same system at the same collision energy and is approximately a factor of 2 higher than the central value calculated with theoretical models. The measured Drell-Yan cross section is in good agreement with next-to-leading-order quantum-chromodynamics calculations.


Nonperturbative-Transverse-Momentum Broadening In Dihadron Angular Correlations In √Snn = 200 Gev Proton-Nucleus Collisions, C. Aidala, Nicole J. Apadula, John C. Hill, Nels J. Hotvedt, John G. Lajoie, Alexandre Lebedev, S. H. Lee, Craig Ogilvie, Milap R. Patel, Joshua Perry, Timothy T. Rinn, Marzia Rosati, Jonathan C. Runchey, Abhisek Sen, M. Shimomura, Arbin Timilsina, Et Al., Phenix Collaboration Apr 2019

Nonperturbative-Transverse-Momentum Broadening In Dihadron Angular Correlations In √Snn = 200 Gev Proton-Nucleus Collisions, C. Aidala, Nicole J. Apadula, John C. Hill, Nels J. Hotvedt, John G. Lajoie, Alexandre Lebedev, S. H. Lee, Craig Ogilvie, Milap R. Patel, Joshua Perry, Timothy T. Rinn, Marzia Rosati, Jonathan C. Runchey, Abhisek Sen, M. Shimomura, Arbin Timilsina, Et Al., Phenix Collaboration

Physics and Astronomy Publications

The PHENIX collaboration has measured high-pT dihadron correlations in p+p, p+Al, and p+Au collisions at √sNN=200 GeV. The correlations arise from inter- and intrajet correlations and thus have sensitivity to nonperturbative effects in both the initial and final states. The distributions of pout, the transverse-momentum component of the associated hadron perpendicular to the trigger hadron, are sensitive to initial- and final-state transverse momenta. These distributions are measured multidifferentially as a function of xE, the longitudinal momentum fraction of the associated hadron with respect to the trigger hadron. The near-side pout widths, sensitive to fragmentation transverse momentum ...


Rotationally Invariant Slave-Boson And Density Matrix Embedding Theory: Unified Framework And Comparative Study On The One-Dimensional And Two-Dimensional Hubbard Model, Tsung-Han Lee, Thomas Ayral, Yong-Xin Yao, Nicola Lanata, Gabriel Kotliar Mar 2019

Rotationally Invariant Slave-Boson And Density Matrix Embedding Theory: Unified Framework And Comparative Study On The One-Dimensional And Two-Dimensional Hubbard Model, Tsung-Han Lee, Thomas Ayral, Yong-Xin Yao, Nicola Lanata, Gabriel Kotliar

Ames Laboratory Accepted Manuscripts

We present detailed benchmark ground-state calculations of the one- and two-dimensional Hubbard model utilizing the cluster extensions of the rotationally invariant slave-boson mean-field theory and the density matrix embedding theory. Our analysis shows that the overall accuracy and the performance of these two methods are very similar. Furthermore, we propose a unified computational framework that allows us to implement both of these techniques on the same footing. This provides us with a different line of interpretation and paves the ways for developing systematically distinct generalizations of these complementary approaches.


Dzyaloshinskii-Moriya Interaction And The Magnetic Ground State In Magnetoelectric Licopo 4, Ellen Fogh, Oksana Zaharko, Jürg Schefer, Christof Niedermayer, Sonja Holm-Dahlin, Michael Korning Sørensen, Andreas Bott Kristensen, Niels Hessel Andersen, David Vaknin, Niels Bech Christensen, Rasmus Toft-Petersen Mar 2019

Dzyaloshinskii-Moriya Interaction And The Magnetic Ground State In Magnetoelectric Licopo 4, Ellen Fogh, Oksana Zaharko, Jürg Schefer, Christof Niedermayer, Sonja Holm-Dahlin, Michael Korning Sørensen, Andreas Bott Kristensen, Niels Hessel Andersen, David Vaknin, Niels Bech Christensen, Rasmus Toft-Petersen

Ames Laboratory Accepted Manuscripts

Magnetic structures are investigated by means of neutron diffraction to shine a light on the intricate details that are believed to be key to understanding the magnetoelectric effect in LiCoPO4. At zero field, a spontaneous spin canting of φ=7(1)∘ is found. The spins tilt away from the easy b-axis toward c. Symmetry considerations lead to the magnetic point group m′z, which is consistent with the previously observed magnetoelectric tensor form and weak ferromagnetic moment along b. For magnetic fields applied along a, the induced ferromagnetic moment couples via the Dzyaloshinskii-Moriya interaction to yield an additional field-induced spin ...


Mg Assisted Flux Growth And Characterization Of Single Crystalline Sm2co17, Tej Nath Lamichhane, Qisheng Lin, Valentin Taufour, Andriy Palasyuk, Tribhuwan Pandey, David Parker, Sergey L. Bud’Ko, Paul C. Canfield Mar 2019

Mg Assisted Flux Growth And Characterization Of Single Crystalline Sm2co17, Tej Nath Lamichhane, Qisheng Lin, Valentin Taufour, Andriy Palasyuk, Tribhuwan Pandey, David Parker, Sergey L. Bud’Ko, Paul C. Canfield

Ames Laboratory Accepted Manuscripts

This paper presents details of Mg-assisted flux growth of Sm2Co17 single crystals in a Ta crucible well below the melting temperature of binary Sm2Co17. Both the crushed single crystalline powder x-ray diffraction (XRD) and single crystalline XRD data revealed the Th2Zn17 type rhombohedral(R-3m) crystal structure. Ta atom is found to be statistically replacing the Co-Co dumbbell with its position being at the center of the dumbbell. The Curie temperature of our lightly Mg and Ta doped Sm2Co17 sample is determined to be ∼1100 K using method of generalized Bloch law fitting of easy axis spontaneous magnetization data.


Energetics Of Cu Adsorption And Intercalation At Graphite Step Edges, Yong Han, Ann Lii-Rosales, Michael C. Tringides, James W. Evans, Patricia A. Thiel Mar 2019

Energetics Of Cu Adsorption And Intercalation At Graphite Step Edges, Yong Han, Ann Lii-Rosales, Michael C. Tringides, James W. Evans, Patricia A. Thiel

Chemistry Publications

To assess the energetics of Cu intercalation on defective graphite, the chemical potentials and binding energies for Cu at graphite step edges are calculated for three main configurations: an isolated atom, a chain, and an atom attached to a chain. As expected, for Cu interacting directly with a graphite step edge, the strength of interaction depends on the stability of the step, with Cu binding more strongly at a less-stable step. However, the relationship is reversed when considering binding of a Cu atom attached to a chain. Taken together, these trends mean that if the graphite step is less stable ...


Ultrafast Nonthermal Terahertz Electrodynamics And Possible Quantum Energy Transfer In The Nb3sn Superconductor, Xu Yang, X. Zhao, Chirag Vaswani, C. Sundahl, Boqun Song, Yong-Xin Yao, Di Cheng, Zhiyan Liu, Peter Orth, M. Mootz, J. H. Kang, I. E. Perakis, Cai-Zhuang Wang, Kai-Ming Ho, C. B. Eom, Jigang Wang Mar 2019

Ultrafast Nonthermal Terahertz Electrodynamics And Possible Quantum Energy Transfer In The Nb3sn Superconductor, Xu Yang, X. Zhao, Chirag Vaswani, C. Sundahl, Boqun Song, Yong-Xin Yao, Di Cheng, Zhiyan Liu, Peter Orth, M. Mootz, J. H. Kang, I. E. Perakis, Cai-Zhuang Wang, Kai-Ming Ho, C. B. Eom, Jigang Wang

Ames Laboratory Accepted Manuscripts

We report terahertz (THz) electrodynamics of a moderately clean A15 superconductor (SC) following ultrafast excitation to manipulate quasiparticle (QP) transport. In the Martensitic normal state, we observe a photo enhancement in the THz conductivity using optical pulses, while the opposite is observed for the THz pump. This demonstrates wavelength-selective nonthermal control of conductivity distinct from sample heating. The photo enhancement persists up to an additional critical temperature, above the SC one, from a competing electronic order. In the SC state, the fluence dependence of pair-breaking kinetics together with an analytic model provides an implication for a “one photon to one ...


Connection Between Mott Physics And Crystal Structure In A Series Of Transition Metal Binary Compounds, Nicola Lanatà, Tsung-Han Lee, Yong-Xin Yao, Vladan Stevanović, Vladimir Dobrosavljević Mar 2019

Connection Between Mott Physics And Crystal Structure In A Series Of Transition Metal Binary Compounds, Nicola Lanatà, Tsung-Han Lee, Yong-Xin Yao, Vladan Stevanović, Vladimir Dobrosavljević

Ames Laboratory Accepted Manuscripts

The choice that a solid system “makes” when adopting a crystal structure (stable or metastable) is ultimately governed by the interactions between electrons forming chemical bonds. Here we analyze six prototypical binary transition metal compounds and shed light on the connection between Mott physics and the behavior of the energy as a function of the spatial arrangement of the atoms in these systems. Remarkably, we find that the main qualitative features of this complex behavior in the Mott phase of these systems can be traced back to the fact that the strong d-electron correlations influence substantially the charge transfer ...


Creation Of Quark–Gluon Plasma Droplets With Three Distinct Geometries, C. Aidala, Nicole J. Apadula, John C. Hill, Nels J. Hotvedt, John G. Lajoie, Alexandre Lebedev, S. H. Lee, Craig Ogilvie, Milap R. Patel, Joshua Perry, Timothy T. Rinn, Marzia Rosati, Jonathan C. Runchey, Abhisek Sen, M. Shimomura, Arbin Timilsina, Et Al., Phenix Collaboration Mar 2019

Creation Of Quark–Gluon Plasma Droplets With Three Distinct Geometries, C. Aidala, Nicole J. Apadula, John C. Hill, Nels J. Hotvedt, John G. Lajoie, Alexandre Lebedev, S. H. Lee, Craig Ogilvie, Milap R. Patel, Joshua Perry, Timothy T. Rinn, Marzia Rosati, Jonathan C. Runchey, Abhisek Sen, M. Shimomura, Arbin Timilsina, Et Al., Phenix Collaboration

Physics and Astronomy Publications

Experimental studies of the collisions of heavy nuclei at relativistic energies have established the properties of the quark–gluon plasma (QGP), a state of hot, dense nuclear matter in which quarks and gluons are not bound into hadrons 1–4 . In this state, matter behaves as a nearly inviscid fluid 5 that efficiently translates initial spatial anisotropies into correlated momentum anisotropies among the particles produced, creating a common velocity field pattern known as collective flow. In recent years, comparable momentum anisotropies have been measured in small-system proton–proton (p+p) and proton–nucleus (p+A) collisions, despite expectations that the ...


Nematicity In The Superconducting Mixed State Of Strain Detwinned Underdoped Ba(Fe1-Xcox)(2)As-2, J. Schmidt, V. Bekeris, G. S. Lozano, M. V. Bortulé, M. Marziali Bermúdez, C. W. Hicks, Paul C. Canfield, E. Fradkin, G. Pasquini Feb 2019

Nematicity In The Superconducting Mixed State Of Strain Detwinned Underdoped Ba(Fe1-Xcox)(2)As-2, J. Schmidt, V. Bekeris, G. S. Lozano, M. V. Bortulé, M. Marziali Bermúdez, C. W. Hicks, Paul C. Canfield, E. Fradkin, G. Pasquini

Ames Laboratory Accepted Manuscripts

Evidence of nematic effects in the mixed superconducting phase of slightly underdoped Ba(Fe1−xCox)2As2 is reported. We have found strong in-plane resistivity anisotropy for crystals in different strain conditions. For these compositions, there is no magnetic long-range order, so the description may be ascribed to the interplay between the superconducting and nematic order parameters. A piezoelectric-based apparatus is used to apply tensile or compressive strain to tune nematic domain orientation in order to examine intrinsic nematicity. Measurements are done under a rotating magnetic field, and the analysis of the angular dependence of physical quantities identifies the cases in ...


Crystal Growth, Microstructure, And Physical Properties Of Srmnsb2, Yong Liu, Tao Ma, Warren E. Straszheim, Farhan Islam, Brandt A. Jensen, Wei Tian, Thomas Heitmann, R. A. Rosenberg, John M. Wilde, Bing Li, Andreas Kreyssig, Alan I. Goldman, Benjamin G. Ueland, Robert J. Mcqueeney, David Vaknin Feb 2019

Crystal Growth, Microstructure, And Physical Properties Of Srmnsb2, Yong Liu, Tao Ma, Warren E. Straszheim, Farhan Islam, Brandt A. Jensen, Wei Tian, Thomas Heitmann, R. A. Rosenberg, John M. Wilde, Bing Li, Andreas Kreyssig, Alan I. Goldman, Benjamin G. Ueland, Robert J. Mcqueeney, David Vaknin

Ames Laboratory Accepted Manuscripts

We report on the crystal and magnetic structures and magnetic and transport properties of SrMnSb2 single crystals grown by the self-flux method. Magnetic susceptibility measurements reveal an antiferromagnetic (AFM) transition at TN=295(3) K. Above TN, the susceptibility slightly increases and forms a broad peak at T∼420 K, which is a typical feature of two-dimensional magnetic systems. Neutron diffraction measurements on single crystals confirm the previously reported C-type AFM structure below TN. Both de Haas-van Alphen (dHvA) and Shubnikov-de Haas (SdH) effects are observed in SrMnSb2 single crystals. Analysis of the oscillatory component by a Fourier transform shows ...


Competition Between Orthorhombic And Re-Entrant Tetragonal Phases In Underdoped Ba1-Xkxfe2as2 Probed By The Response To Controlled Disorder, Erik I. Timmons, Makariy A. Tanatar, K. Willa, S. Teknowijoyo, Kyuil Cho, M. Konczykowski, O. Cavani, Yong Liu, Thomas A. Lograsso, U. Welp, Ruslan Prozorov Feb 2019

Competition Between Orthorhombic And Re-Entrant Tetragonal Phases In Underdoped Ba1-Xkxfe2as2 Probed By The Response To Controlled Disorder, Erik I. Timmons, Makariy A. Tanatar, K. Willa, S. Teknowijoyo, Kyuil Cho, M. Konczykowski, O. Cavani, Yong Liu, Thomas A. Lograsso, U. Welp, Ruslan Prozorov

Ames Laboratory Accepted Manuscripts

Low-temperature (22 K) irradiation with 2.5-MeV electrons, creating point defects affecting elastic scattering, was used to study the competition between stripe C-2 and tetragonal C-4 antiferromagnetic phases which exist in a narrow doping range around x = 0.25 in hole-doped Ba1-xKxFe2As2. In nearby compositions outside of this range, at x = 0.22 and x = 0.19, the temperatures of both the concomitant orthorhombic/stripe antiferromagnetic transition T-C2 and the superconducting transition T-c are monotonically suppressed by added disorder at similar rates of about 0.1 K/mu Omega cm, as revealed through using resistivity variation as an intrinsic measure ...


From Tb3ni2 To Tb3coni: The Interplay Between Chemistry, Structure, And Magnetism, Clemens Ritter, Alessia Provino, Francois Fauth, Sudesh K. Dhar, Vitalij K. Pecharsky, Pietro Manfrinetti Feb 2019

From Tb3ni2 To Tb3coni: The Interplay Between Chemistry, Structure, And Magnetism, Clemens Ritter, Alessia Provino, Francois Fauth, Sudesh K. Dhar, Vitalij K. Pecharsky, Pietro Manfrinetti

Ames Laboratory Accepted Manuscripts

Formation, crystal structure, and macroscopic and microscopic magnetism of the binary Tb3Ni2 and derivative pseudobinary Tb3CoxNi2−x phases have been investigated using an array of experimental methods. While Tb3Ni2 crystallizes in the monoclinic Dy3Ni2 structure type (mS20, C2/m), the substitution of Co for Ni results in a structural transition into the rhombohedral Er3Ni2 type (hR45, R¯3h) at x(Co)≈0.34 and beyond in the Tb3CoxNi2−x system. In both the monoclinic and rhombohedral phases, the addition of Co leads to an anisotropic change of lattice parameters and unexpected reduction of the cell volume. Measurements of bulk properties ...


Revealing The Nature Of Antiferroquadrupolar Ordering In Cerium Hexaboride: Ceb6, C. K. Barman, Prashant Singh, Duane Johnson, Aftab Alam Feb 2019

Revealing The Nature Of Antiferroquadrupolar Ordering In Cerium Hexaboride: Ceb6, C. K. Barman, Prashant Singh, Duane Johnson, Aftab Alam

Ames Laboratory Accepted Manuscripts

The cerium hexaboride (CeB6) f-electron compound displays a rich array of low-temperature magnetic phenomena, including a “magnetically hidden” order, identified as multipolar in origin via advanced x-ray scattering. From first-principles electronic-structure results, we find that the antiferroquadrupolar(AFQ) ordering in CeB6 arises from crystal-field splitting and yields a band structure in agreement with experiments. With interactions of p electrons between Ce and B6 being small, the electronic state of CeB6 is suitably described as Ce(4f1)3+(e−)(B6)2−. The AFQ state of orbital spins is caused by an exchange interaction induced through spin-orbit interaction, which also splits the ...


Intersublattice Magnetocrystalline Anisotropy Using A Realistic Tight-Binding Method Based On Maximally Localized Wannier Functions, Liqin Ke Feb 2019

Intersublattice Magnetocrystalline Anisotropy Using A Realistic Tight-Binding Method Based On Maximally Localized Wannier Functions, Liqin Ke

Ames Laboratory Accepted Manuscripts

Using a realistic tight-binding Hamiltonian based on maximally localized Wannier functions, we investigate the two-ion magnetocrystalline anisotropy energy (MAE) in L10 transition metal compounds. MAE contributions from throughout the Brillouin zone are obtained using magnetic force theorem calculations with and without perturbation theory. The results from both methods agree with each other, and both reflect features of the Fermi surface. The intrasublattice and intersublattice contributions to MAE are evaluated using a Green's function method. We find that the sign of the intersublattice contribution varies among compounds, and that its amplitude may be significant, suggesting MAE can not ...