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  • Band structure of cavity-type hypersonic phononic crystals fabricated by femtosecond laser-induced two-photon polymerization 
    Rakhymzhanov, A. M.; Gueddida, A.; Alonso-Redondo, E.; Utegulov, Zhandos; Perevoznik, D.; Kurselis, K.; Chichkov, B. N.; El Boudouti, E. H.; Djafari-Rouhani, B.; Fytas, G. (Applied Physics Letters, 2016-05)
    The phononic band diagram of a periodic square structure fabricated by femtosecond laser pulseinduced two photon polymerization is recorded by Brillouin light scattering (BLS) at hypersonic (GHz) frequencies and computed ...
  • Assessing performance of modern Brillouin spectrometers 
    Coker, Zachary; Troyanova‐Wood, Maria; Traverso, Andrew J.; Yakupov, Talgat; Utegulov, Zhandos; Yakovlev, Vladislav V. (Optics Express, 2018-02)
    Brillouin spectroscopy and imaging has experienced a renaissance in recent years seeing vast improvements in methodology and increasing number of applications. With this resurgence has come the development of new spontaneous ...
  • Size effects in near-ultraviolet Raman spectra of few-nanometer-thick silicon-oninsulator nanofilms 
    Poborchii, Vladimir; Morita, Yukinori; Tada, Tetsuya; Geshev, Pavel I.; Utegulov, Zhandos; Volkov, Alexey (Journal of Applied Physics, 2016-04)
    We have fabricated Si-on-insulator (SOI) layers with a thickness h1 of a few nanometers and examined them by Raman spectroscopy with 363.8 nm excitation. We have found that phonon and electron confinement play important ...
  • Laser thermoelastic generation in metals above the melt threshold 
    Every, A. G.; Utegulov, Zhandos; Veres, I. A. (Journal of Applied Physics, 2013-11)
    An approach is presented for calculating thermoelastic generation of ultrasound in a metal plate exposed to nanosecond pulsed laser heating, sufficient to cause melting but not ablation. Detailed consideration is given to ...
  • Nonlinear waves in hyperbolic metamaterials: focus on solitons and rogues 
    Boardman, A.D.; Grimalsky, V.V.; Guo, T.; Kibler, B.; McNiff, J.; Nefedov, I.; Rapoport, Y.; Argyropoulos, C.; Valagiannopoulos, Constantinos (Nazarbayev University School of Science and Technology, 2018-05-07)
    The investigation of hyperbolic metamaterials, shows that metal layers that are part of graphene structures, and also types I and II layered systems, are readily controlled. Since graphene is a nicely conducting sheet it ...
  • Analytical investigations of ground modifications assisting the detection of buried object 
    Valagiannopoulos, Constantinos; Tsitsas, Nikolaos L.; Sihvola, Ari H. (Nazarbayev University School of Science and Technology, 2016-08-18)
    A ground-penetrating radar (GPR) antenna excites a perfectly electric conducting inclusion buried inside the ground. The scattering problem is solved semi-analytically via integral equation techniques. The permittivity and ...
  • Photonic crystals for optimal color conversion in light-emitting diodes: a semi-analytical approach 
    Valagiannopoulos, Constantinos; Lagoudakis, Pavlos G. (Nazarbayev University School of Science and Technology, 2018-04-13)
    Based on effective-medium approximation, we analytically optimize the color conversion of GaN-based light-emitting p–n junctions, with respect to the size and spatial density of the used photonic crystals (PhCs), being ...
  • Cooperative surmounting of bottlenecks 
    Hennig, D.; Mulhern, C.; Schimansky-Geier, L.; Tsironis, G.P.; Hänggi, P. (Physics Reports, 2015-07-20)
    Abstract The physics of activated escape of objects out of a metastable state plays a key role in diverse scientific areas involving chemical kinetics, diffusion and dislocation motion in solids, nucleation, electrical ...
  • Stochastic metastability by spontaneous localisation 
    Oikonomou, Th.; Nergis, A.; Lazarides, N.; Tsironis, G.P. (Chaos, Solitons & Fractals, 2014-12-01)
    Abstract Nonequilibrium, quasi-stationary states of a one-dimensional “hard” ϕ4 deterministic lattice, initially thermalised to a particular temperature, are investigated when brought into contact with a stochastic thermal ...
  • Lithium CPS based on carboxylic fabric with CNT synthesized on its fibers’ surface 
    Zaurbekova, Z.; Chikhray, Y.; Ponkratov, Y.; Baklanov, V.; Abdullin, K.; Kulsartov, T.; Gordienko, Y.; Tazhibayeva, I.; Skakov, M.; Mukanova, A. (Materials Today: Proceedings, 2017-01-01)
    Abstract The paper describes a technique of CNT synthesis on the fibers of carboxylic fabric. It consists of three operational stages: creation of the experimental facility based on high-temperature quartz flow reactor; ...
  • Self-induced transparency of the optical phonons 
    Mandilara, Aikaterini; Ivić, Zoran; Čevizović, Dalibor; Pržulj, Željko (Chaos, Solitons & Fractals, 2017-12-01)
    Abstract We show that the self-induced transparency of optical phonons may appear in a systems consisting of a two level atoms interacting with elastic waves. The presence of the gap in phonon spectrum substantially enhances ...
  • Effects of internal stresses and intermediate phases on the coarsening of coherent precipitates: A phase-field study 
    Asle Zaeem, M.; El Kadiri, H.; Horstemeyer, M.F.; Khafizov, M.; Utegulov, Z. (Current Applied Physics, 2012-03-01)
    Abstract Phase stability, topology and size evolution of precipitates are important factors in determining the mechanical properties of crystalline materials. In this article, the Cahn–Hilliard type of phase-field model ...
  • “Isotope effect” of hydrogen and deuterium interaction with vanadium alloys VCrTi 
    Kenzhina, I.; Kulsartov, T.; Chikhray, Y.; Shestakov, V.; Tolebay, A.; Askerbekov, S.; Tazhibayeva, I.; Gordienko, Y.; Ponkratov, Y.; Zaurbekova, Zh.; Mukanova, A. (Materials Today: Proceedings, 2017-01-01)
    Abstract V-Ti-Cr vanadium alloys have many perspective applications, particularly, they are considered as a main structural material of the first wall and blanket of fusion reactor with lithium coolant. Also, they are used ...
  • Group theory, entropy and the third law of thermodynamics 
    Canturk, Bilal; Oikonomou, Thomas; Bagci, G. Baris (Annals of Physics, 2017-02-01)
    Abstract Curado et al. (2016) have recently studied the axiomatic structure and the universality of a three-parameter trace-form entropy inspired by the group-theoretical structure. In this work, we study the group-theoretical ...
  • Universal all-particle explicitly-correlated Gaussians for non-Born–Oppenheimer calculations of molecular rotationless states 
    Bubin, Sergiy; Formanek, Martin; Adamowicz, Ludwik (Chemical Physics Letters, 2016-03-01)
    Abstract Complex explicitly correlated one-center all-particle Gaussian functions (CECGs) are tested as basis functions for molecular non-Born–Oppenheimer (non-BO) calculations. The tests concern the complete spectrum of ...
  • Singlet–triplet energy splitting between 1D and 3D (1s22snd), n=3, 4, 5, and 6, Rydberg states of the beryllium atom (9Be) calculated with all-electron explicitly correlated Gaussian functions 
    Sharkey, Keeper L.; Bubin, Sergiy; Adamowicz, Ludwik (Chemical Physics Letters, 2014-11-25)
    Abstract Accurate variational nonrelativistic quantum-mechanical calculations are performed for the five lowest 1D and four lowest 3D states of the 9Be isotope of the beryllium atom. All-electron explicitly correlated ...
  • Relaxation of non-isothermal hot dense plasma parameters 
    Kodanova, S.K.; Issanova, M.K.; Amirov, S.M.; Ramazanov, T.S.; Tikhonov, A.; Moldabekov, Zh.A. (Matter and Radiation at Extremes, 2017-09-06)
    Abstract The relaxation of temperature, coupling parameters, the excess part of equation of state, and the correlation energy of the non-isothermal hot dense plasmas are considered on the basis of the method of effective ...
  • Intrinsic photoluminescence Stokes shift in semiconductors demonstrated by thin-film CdS formed with pulsed-laser deposition 
    Ullrich, B.; Ariza-Flores, D.; Bhowmick, M. (Thin Solid Films, 2014-05-02)
    Abstract While not reported in the literature, by employing highly oriented, semi-insulating, thin-film CdS as test material, we present the observation of the intrinsic photoluminescence Stokes shift in a semiconductor. ...
  • Misusing the entropy maximization in the jungle of generalized entropies 
    Oikonomou, Thomas; Bagci, G. Baris (Physics Letters A, 2017-01-30)
    Abstract It is well-known that the partition function can consistently be factorized from the canonical equilibrium distribution obtained through the maximization of the Shannon entropy. We show that such a normalized and ...
  • Wide-angle absorption of visible light from simple bilayers 
    PAPADIMOPOULOS, ATHANASIOS N.; KANTARTZIS, NIKOLAOS V.; TSITSAS, NIKOLAOS L.; Valagiannopoulos, Constantinos (Optical Society of America, 2017-12-08)
    Color-selective absorption of light is a very significant operation used in numerous applications, from photonic sensing and switching to optical signal modulation and energy harnessing. We demonstrate angle-insensitive ...