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We show that hexagonal boron nitride (hBN), a two-dimensional insulator, when subjected to an external superlattice potential forms a new paradigm for electrostatically tunable excitons in the near- and mid-ultraviolet (UV). The imposed…

Mesoscale and Nanoscale Physics · Physics 2024-08-08 Pedro Ninhos , Christos Tserkezis , N. Asger Mortensen , Nuno M. R. Peres

A new interpretation of the optical and energy-loss spectra of hexagonal boron nitride is provided based on first-principle calculations. We show that both spectra cannot be explained by independent-particle transitions but are strongly…

Materials Science · Physics 2007-05-23 Ludger Wirtz , Andrea Marini , Myrta Gruning , Angel Rubio

Excitons -- elementary excitations formed by bound electron-hole pairs -- govern the optical properties and excited-state dynamics of materials. In two-dimensions (2D), excitons are theoretically predicted to have a linear energy-momentum…

Materials Science · Physics 2025-03-14 Luna Y. Liu , Steffi Y. Woo , Jinyuan Wu , Bowen Hou , Cong Su , Diana Y. Qiu

Dielectric breakdown has historically been of great interest from the perspectives of fundamental physics and electrical reliability. However, to date, the anisotropy in the dielectric breakdown has not been discussed. Here, we report an…

Materials Science · Physics 2016-11-01 Yoshiaki Hattori , Takashi Taniguchi , Kenji Watanabe , Kosuke Nagashio

We combine electron energy-loss spectroscopy and first-principles calculations based on density-functional theory (DFT) to identify the lowest indirect exciton state in the in-plane charge response of hexagonal boron nitride (h-BN) single…

Mesoscale and Nanoscale Physics · Physics 2018-01-10 R. Schuster , C. Habenicht , M. Ahmad , M. Knupfer , B. Büchner

Hexagonal boron nitride (hBN) is attracting a lot of attention in the last years, thanks to its many remarkable properties. These include the presence of single-photon emitters with superior optical properties, which make it an ideal…

Understanding and controlling the way excitons propagate in solids is a key for tailoring materials with improved optoelectronic properties. A fundamental step in this direction is the determination of the exciton energy-momentum…

In this letter we report a thorough analysis of the exciton dispersion in bulk hexagonal boron nitride. We solve the ab initio GW Bethe-Salpeter equation at finite $\mathbf{q}\parallel \Gamma K$, and we compare our results with recent…

Mesoscale and Nanoscale Physics · Physics 2018-02-22 Lorenzo Sponza , Hakim Amara , Claudio Attaccalite , François Ducastelle , Annick Loiseau

The electronic and optical properties of 2D hexagonal boron nitride are studied using first principle calculations. GW and BSE methods are employed in order to predict with better accuracy the excited and excitonic properties of this…

Mesoscale and Nanoscale Physics · Physics 2019-02-20 F. Ferreira , A. J. Chaves , N. M. R. Peres , R. M. Ribeiro

A new interlayer force-field for layered hexagonal boron nitride (h-BN) based structures is presented. The force-field contains three terms representing the interlayer attraction due to dispersive interactions, repulsion due to anisotropic…

Materials Science · Physics 2014-03-13 Itai Leven , Ido Azuri , Leeor Kronik , Oded Hod

We compute and discuss the electronic band structure and excitonic dispersion of hexagonal boron nitride (hBN) in the single layer configuration and in three bulk polymorphs (usual AA' stacking, Bernal AB, and rhombohedral ABC). We focus on…

Hexagonal boron nitride (hBN) has been attracting great attention because of its strong excitonic effects. Taking into account few-layer systems, we investigate theoretically the effects of the number of layers on quasiparticle energies,…

Hexagonal boron nitride (hBN) plays a central role in nanoelectronics and nanophotonics. Moreover, hBN hosts room-temperature quantum emitters and optically addressable spins, making it promising for quantum sensing and quantum photonics.…

A quantitative analysis of the excitonic luminescence efficiency in hexagonal boron nitride (hBN) is carried out by cathodoluminescence in the ultraviolet range and compared with zinc oxide and diamond single crystals. A high quantum yield…

The negatively charged boron vacancy (VB-) in hexagonal boron nitride (hBN) has been extensively investigated as it offers a novel playground for two-dimensional quantum sensing, with ultimate proximity to target samples. However, its…

Hexagonal boron nitride (BN) is widely used as a substrate and gate insulator for two-dimensional (2D) electronic devices. The studies on insulating properties and electrical reliability of BN itself, however, are quite limited. Here, we…

Materials Science · Physics 2015-10-08 Y. Hattori , K. Watanabe , T. Taniguchi , K. Nagashio

There has been growing interest in studying hexagonal boron nitride (hBN) for quantum technologies. Here, we investigate nitrogen isotope effects on boron vacancy (V$_\text{B}$) defects, one of the candidates for quantum sensors, in…

Quantum Physics · Physics 2023-09-25 Kento Sasaki , Takashi Taniguchi , Kensuke Kobayashi

The electrical evaluation of the crystallinity of hexagonal boron nitride (h-BN) is still limited to the measurement of dielectric breakdown strength, in spite of its importance as the substrate for 2-dimensional van der Waals…

Materials Science · Physics 2018-01-29 Y. Hattori , T. Taniguchi , K. Watanabe , K. Nagashio

Hexagonal boron nitride (hBN) is a wide band gap material with both strong excitonic light emission in the ultraviolet and strong exciton-phonon coupling. Luminescence experiments performed on the recently synthesized monolayer form (m-hBN)…

Materials Science · Physics 2023-02-28 Pierre Lechifflart , Fulvio Paleari , Davide Sangalli , Claudio Attaccalite

We examine the effect of a hexagonal boron nitride (hBN) substrate on electron transport through graphene nanojunctions just before gap formation. Junctions in vacuum and on hBN are formed using classical molecular dynamics to create…

Mesoscale and Nanoscale Physics · Physics 2016-06-29 Hatef Sadeghi , Sara Sangtarash , Colin Lambert
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