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Full-Text Articles in Physics
Silicene-Like Domains On Irsi3 Crystallites, Dylan Nicholls, Fnu Fatima, Deniz Cakir, Nuri Oncel
Silicene-Like Domains On Irsi3 Crystallites, Dylan Nicholls, Fnu Fatima, Deniz Cakir, Nuri Oncel
Physics Faculty Publications
Recently, silicene, the graphene equivalent of silicon, has attracted a lot of attention due to its compatibility with Si-based electronics. So far, silicene has been epitaxy grown on various crystalline surfaces such as Ag(110), Ag(111), Ir(111), ZrB2(0001) and Au(110) substrates. Here, we present a new method to grow silicene via high temperature surface reconstruction of hexagonal IrSi3 nanocrystals. The h-IrSi3 nanocrystals are formed by annealing thin Ir layers on Si(111) surface. A detailed analysis of the STM images shows the formation of silicene like domains on the surface of some of the IrSi3 crystallites. We studied both morphology and electronic …
Dark Energy Survey Year 1 Results: Cosmological Constraints From Galaxy Clustering And Weak Lensing, T. M. C. Abbott, F. B. Abdalla, A. Alarcon, J. Aleksic, S. Allam, S. Allen, A. Amara, J. Annis, J. Asorey, S. Avila, D. Bacon, E. Balbinot, M. Banerji, N. Banik, Wayne Barkhouse
Dark Energy Survey Year 1 Results: Cosmological Constraints From Galaxy Clustering And Weak Lensing, T. M. C. Abbott, F. B. Abdalla, A. Alarcon, J. Aleksic, S. Allam, S. Allen, A. Amara, J. Annis, J. Asorey, S. Avila, D. Bacon, E. Balbinot, M. Banerji, N. Banik, Wayne Barkhouse
Physics Faculty Publications
We present cosmological results from a combined analysis of galaxy clustering and weak gravitational lensing, using 1321 deg2 of griz imaging data from the first year of the Dark Energy Survey (DES Y1). We combine three two-point functions: (i) the cosmic shear correlation function of 26 million source galaxies in four redshift bins, (ii) the galaxy angular autocorrelation function of 650,000 luminous red galaxies in five redshift bins, and (iii) the galaxy-shear cross-correlation of luminous red galaxy positions and source galaxy shears. To demonstrate the robustness of these results, we use independent pairs of galaxy shape, photometric-redshift estimation and validation, …
Mapping Star Formation From The Core To The Outskirts Of Galaxy Clusters, Wayne Barkhouse, Gihan Gamage, Sandanuwa Kalawila, Madina Sultanova, Dean Smith, Elijah Mathews, Haylee Archer
Mapping Star Formation From The Core To The Outskirts Of Galaxy Clusters, Wayne Barkhouse, Gihan Gamage, Sandanuwa Kalawila, Madina Sultanova, Dean Smith, Elijah Mathews, Haylee Archer
Physics Faculty Publications
We propose for time to complete our u- and r-band imaging program of 30 low-redshift (z ≤ 0.03) galaxy clusters using the CTIO Blanco 4m+DECam telescope/detector combination. These data will allow us to probe star formation from the cluster core to the infall region, and complete the acquisition of observations for the Ph.D. dissertation of Gihan Gamage (University of North Dakota). The deep u- and r-band data will allow us to explore relative changes in the luminosity function, dwarf-to-giant ratio, blue fraction, and galaxy morphological type as a function of cluster-centric radius for a statistically significant sample of 30 clusters. …
U-Band Measurement Of Star Formation In Cluster Galaxies, Wayne Barkhouse, Gihan Gamage, Sandanuwa Kalawila, Madina Sultanova, Dean Smith, Elijah Mathews, Haylee Archer
U-Band Measurement Of Star Formation In Cluster Galaxies, Wayne Barkhouse, Gihan Gamage, Sandanuwa Kalawila, Madina Sultanova, Dean Smith, Elijah Mathews, Haylee Archer
Physics Faculty Publications
We propose to obtain deep U-band observations of 14 low-redshift (z ≤ 0.06) galaxy clusters using the WIYN 0.9m+HDI telescope/detector to complete our survey to probe star formation of galaxies in high-density environments. These observations, combined with previously obtained data of 11 clusters observed using the same telescope+detector, will give us a statistically significant sample for the Ph.D. dissertation of co-I Gihan Gamage. Clusters are selected from 57 clusters in which we have obtained deep B- and R-band data using the KPNO 0.9m+MOSA. U-band data will allow us to explore relative changes in the luminosity function for the U- and …
Intercalation Of Si Between Mos2 Layers, Rik Van Bremen, Qirong Yao, Soumya Banerjee, Deniz Cakir, Nuri Oncel, Harold J.W. Zandvliet
Intercalation Of Si Between Mos2 Layers, Rik Van Bremen, Qirong Yao, Soumya Banerjee, Deniz Cakir, Nuri Oncel, Harold J.W. Zandvliet
Physics Faculty Publications
We report a combined experimental and theoretical study of the growth of sub-monolayer amounts of silicon (Si) on molybdenum disulfide (MoS2). At room temperature and low deposition rates we have found compelling evidence that the deposited Si atoms intercalate between the MoS2 layers. Our evidence relies on several experimental observations: (1) Upon the deposition of Si on pristine MoS2 the morphology of the surface transforms from a smooth surface to a hill-and-valley surface. The lattice constant of the hill-and-valley structure amounts to 3.16 Å, which is exactly the lattice constant of pristine MoS2. (2) The transitions from hills to valleys …
Superconductor-Insulator Transition And Fermi-Bose Crossovers, Yen Lee Loh, Mohit Randeria, Nandini Trivedi, Chia-Chen Chang, Richard Scalettar
Superconductor-Insulator Transition And Fermi-Bose Crossovers, Yen Lee Loh, Mohit Randeria, Nandini Trivedi, Chia-Chen Chang, Richard Scalettar
Physics Faculty Publications
The direct transition from an insulator to a superconductor (SC) in Fermi systems is a problem of long-standing interest, which necessarily goes beyond the standard BCS paradigm of superconductivity as a Fermi surface instability. We introduce here a simple, translationally invariant lattice fermion model that undergoes a SC-insulator transition (SIT) and elucidate its properties using analytical methods and quantum Monte Carlo simulations. We show that there is a fermionic band insulator to bosonic insulator crossover in the insulating phase and a BCS-to-BEC crossover in the SC. The SIT is always found to be from a bosonic insulator to a BEC-like …