Radiative properties of quantum emitters in boron nitride from excited state calculations and Bayesian analysis

AbstractPoint defects in hexagonal boron nitride (hBN) have attracted growing attention as bright single-photon emitters. However, understanding of their atomic structure and radiative properties remains incomplete. Here we study the excited states and radiative lifetimes of over 20 native defects and carbon or oxygen impurities in hBN using ab initio density functional theory and GW plus Bethe-Salpeter equation calculations, generating a large data set of their emission energy, polarization and lifetime. We find a wide variability across quantum emitters, with exciton energies ranging from 0.3 to 4 eV and radiative lifetimes from ns to ms for different defect structures. Through a Bayesian statistical analysis, we identify various high-likelihood charge-neutral defect emitters, among which the native VNNB defect is predicted to possess emission energy and radiative lifetime in agreement with experiments. Our work advances the microscopic understanding of hBN single-photon emitters and introduces a computational framework to characterize and identify quantum emitters in 2D materials.

Download Full-text

Donor-Acceptor Pair Quantum Emitters in Hexagonal Boron Nitride

10.21203/rs.3.rs-963501/v1 ◽

2021 ◽

Author(s):

Qinghai Tan ◽

Jia-Min Lai ◽

Xue-Lu Liu ◽

Dan Guo ◽

Yong-Zhou Xue ◽

...

Keyword(s):

Boron Nitride ◽

Single Photon ◽

Hexagonal Boron Nitride ◽

Visible Spectrum ◽

Conclusive Evidence ◽

Fingerprint Matching ◽

Acceptor Pair ◽

Single Photon Emitters ◽

Donor Acceptor ◽

Quantum Emitters

Abstract Quantum emitters are needed for a myriad of applications ranging from quantum sensing to quantum computing. Hexagonal boron nitride (hBN) quantum emitters are the most promising solid-state platform to date due to its high brightness, stability, and the possibility of spin photon interface. However, the understanding of the physical origins of the single-photon emitters (SPEs) is still limited. Here, we present concrete and conclusive evidence that the dense SPEs in hBN, across entire visible spectrum, can be well explained by donor-acceptor pairs (DAPs). Based on the DAP transition generation mechanism, we have calculated their wavelength fingerprint, matching well with the experimentally observed photoluminescence spectrum. Our work serves as a step forward for the physical understanding of SPEs in hBN and their applications in quantum technologies.

Download Full-text

Substitutional impurities in monolayer hexagonal boron nitride as single-photon emitters

Nanomaterials and Nanotechnology ◽

10.1177/1847980420949349 ◽

2020 ◽

Vol 10 ◽

pp. 184798042094934

Author(s):

Michele Re Fiorentin ◽

Kiptiemoi Korir Kiprono ◽

Francesca Risplendi

Keyword(s):

Boron Nitride ◽

Density Functional ◽

Single Photon ◽

Hexagonal Boron Nitride ◽

Photon Emission ◽

Single Photon Emission ◽

Defect States ◽

Impurity Atoms ◽

Single Photon Emitters ◽

Substitutional Impurities

Single-photon emitters in hexagonal boron nitride have attracted great attention over the last few years due to their excellent optoelectronical properties. Despite the vast range of results reported in the literature, studies on substitutional impurities belonging to the 13th and 15th groups have not been reported yet. Here, through theoretical modeling, we provide direct evidence that hexagonal boron nitride can be opportunely modified by introducing impurity atoms such as aluminum or phosphorus that may work as color centers for single-photon emission. By means of density functional theory, we focus on determining the structural stability, induced strain, and charge states of such defects and discuss their electronic properties. Nitrogen substitutions with heteroatoms of group 15 are shown to provide attractive features (e.g. deep defect levels and localized defect states) for single-photon emission. These results may open up new possibilities for employing innovative quantum emitters based on hexagonal boron nitride for emerging applications in nanophotonics and nanoscale sensing devices.

Download Full-text

Optical quantum technologies with hexagonal boron nitride single photon sources

Scientific Reports ◽

10.1038/s41598-021-90804-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Akbar Basha Dhu-al-jalali-wal-ikram Shaik ◽

Penchalaiah Palla

Keyword(s):

Boron Nitride ◽

Density Functional ◽

Light Emission ◽

Single Photon ◽

Hexagonal Boron Nitride ◽

Photon Emission ◽

Building Blocks ◽

Wide Range ◽

Photon Sources ◽

Quantum Emitters

AbstractSingle photon quantum emitters are important building blocks of optical quantum technologies. Hexagonal boron nitride (hBN), an atomically thin wide band gap two dimensional material, hosts robust, optically active luminescent point defects, which are known to reduce phonon lifetimes, promises as a stable single-photon source at room temperature. In this Review, we present the recent advances in hBN quantum light emission, comparisons with other 2D material based quantum sources and analyze the performance of hBN quantum emitters. We also discuss state-of-the-art stable single photon emitter’s fabrication in UV, visible and near IR regions, their activation, characterization techniques, photostability towards a wide range of operating temperatures and harsh environments, Density-functional theory predictions of possible hBN defect structures for single photon emission in UV to IR regions and applications of single photon sources in quantum communication and quantum photonic circuits with associated potential obstacles.

Download Full-text

Position-controlled quantum emitters with reproducible emission wavelength in hexagonal boron nitride

Nature Communications ◽

10.1038/s41467-021-24019-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Clarisse Fournier ◽

Alexandre Plaud ◽

Sébastien Roux ◽

Aurélie Pierret ◽

Michael Rosticher ◽

...

Keyword(s):

Boron Nitride ◽

Single Photon ◽

Hexagonal Boron Nitride ◽

Photon Emission ◽

Spatial Location ◽

Emission Wavelength ◽

Visible Range ◽

Single Photon Emitters ◽

Low Dimensional ◽

Quantum Emitters

AbstractSingle photon emitters (SPEs) in low-dimensional layered materials have recently gained a large interest owing to the auspicious perspectives of integration and extreme miniaturization offered by this class of materials. However, accurate control of both the spatial location and the emission wavelength of the quantum emitters is essentially lacking to date, thus hindering further technological steps towards scalable quantum photonic devices. Here, we evidence SPEs in high purity synthetic hexagonal boron nitride (hBN) that can be activated by an electron beam at chosen locations. SPE ensembles are generated with a spatial accuracy better than the cubed emission wavelength, thus opening the way to integration in optical microstructures. Stable and bright single photon emission is subsequently observed in the visible range up to room temperature upon non-resonant laser excitation. Moreover, the low-temperature emission wavelength is reproducible, with an ensemble distribution of width 3 meV, a statistical dispersion that is more than one order of magnitude lower than the narrowest wavelength spreads obtained in epitaxial hBN samples. Our findings constitute an essential step towards the realization of top-down integrated devices based on identical quantum emitters in 2D materials.

Download Full-text