Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
Browse
Search Results
Article The Temperature Dependence of Elastic Constants and Zener Anisotropy in Single Crystal KTaO3 Below Room Temperature(Pleiades Publishing Ltd, 2025) Li, C. H.; Ding, X. D.; Carpenter, M. A.; Aktas, O.We present the first experimental report of the complete elastic tensor of incipient ferroelectric KTaO3 between 9.6 and 307 K, using resonant ultrasound spectroscopy (RUS). The elastic constants C-11 and C-44, as well as the bulk and shear moduli increase roughly linearly upon cooling. Deviations from such dependence are a result of impurities. Zener anisotropy factor is 0.697 at room temperature and decreases to 0.627 at 9.6 K, indicating increasing elastic anisotropy. The temperature dependence of C-12 is anomalous with no stiffening on cooling, which could be a result of different defect species influencing C-12 but not the other constants, possibly due to defect anisotropy. The values of elastic constants and anisotropy are compared at room temperature and below 10 K with the literature reporting experimental results and density functional theory calculations.Article Time-Resolved Stokes Polarization Analysis of Single Photon Emitters in Hexagonal Boron Nitride(American Chemical Society, 2025) Samaner, C.; Ateş, S.Solid-state quantum emitters are pivotal to the advancement of quantum technologies, particularly in quantum computation and communication, where the polarization of single photons serves as a key information carrier. Precise characterization of polarization is essential for understanding the underlying dynamics and minimizing polarization-related errors in emitter design. In this study, we employ the Rotating Quarter-Wave Plate (RQWP) method to perform comprehensive polarization analysis of quantum emitters in hexagonal boron nitride (hBN). By capturing both time-averaged and time-resolved polarization characteristics, we present the first demonstration of dynamic Stokes parameter evolution from single-photon emitters in hBN. Our work demonstrates a powerful method for revealing complex polarization dynamics that were previously inaccessible and provides new insights into the behavior of solid-state quantum emitters. The methods introduced here are broadly applicable to polarization studies across a range of solid-state quantum systems. © 2025 Elsevier B.V., All rights reserved.Article Citation - WoS: 2Citation - Scopus: 2Temperature-Dependent Spectral Properties of Hexagonal Boron Nitride Color Centers(Amer Chemical Soc, 2025) Ari, Ozan; Polat, Nahit; Firat, Volkan; Cakir, Ozgur; Ates, SerkanColor centers in hexagonal boron nitride (hBN) are emerging as a mature platform for single-photon sources in quantum technology applications. In this study, we investigate the temperature-dependent spectral properties of a single defect in hBN to understand the dominant dephasing mechanisms due to phonons. We observe a sharp zero-phonon line (ZPL) emission accompanied by Stokes and anti-Stokes optical phonon sidebands assisted by the Raman-active low-energy (approximate to 6.5 meV) interlayer shear mode of hBN. The shape of the spectral lines around the ZPL is measured down to 78 K, at which the line width of the ZPL is measured as 211 mu eV. Using a quadratic electron-phonon interaction, the temperature-dependent broadening and the lineshift of the ZPL are found to follow a temperature dependence of T + T 5 and T + T 3, respectively. Furthermore, the temperature-dependent line shape around the ZPL at low-temperature conditions is modeled with a linear electron-phonon coupling theory, which results in a 0 K Debye-Waller factor of the ZPL emission as 0.59. Our results provide insights into the underlying mechanisms of electron-phonon coupling in hBN, which is critical to enhance their potential for applications in quantum technologies.