@article{Samaner_2025,
title = {Time-Resolved Stokes Analysis of Single Photon Emitters in Hexagonal Boron Nitride},
author = {Çağlar Samaner, Serkan Ateş},
url = {https://arxiv.org/abs/2504.11193},
doi = {10.48550/arXiv.2504.11193},
year = {2025},
date = {2025-04-15},
journal = {arXiv:2504.11193},
abstract = {Solid-state quantum emitters play a vital role in advancing quantum technologies, particularly in quantum computation and communication, where single-photon polarization acts as a fundamental information carrier. Precise polarization characterization is essential for understanding the mechanisms underlying polarization dynamics, which is critical for developing quantum emitters with minimized polarization-related errors. In this study, we employ the Rotating Quarter-Wave Plate (RQWP) method to comprehensively characterize the polarization state of quantum emitters in hexagonal boron nitride (hBN). By examining both time-averaged and dynamic polarization features, we demonstrate the time-resolved evolution of Stokes parameters from a solid-state single-photon emitter using the RQWP technique. This approach provides more complete polarization information than conventional micro-photoluminescence methods, without requiring modifications to the experimental setup. Our results uncover intricate polarization dynamics in hBN emitters, offering insights that were previously inaccessible. The techniques presented here can be broadly applied to polarization analysis of solid-state quantum emitters across various material platforms.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Caglar2024,
title = {Polarization Dynamics of Solid-State Quantum Emitters},
author = {Anand Kumar and Çağlar Samaner and Chanaprom Cholsuk and Tjorben Matthes and Serkan Paçal and Yağız Oyun and Ashkan Zand and Robert J. Chapman and Grégoire Saerens and Rachel Grange and Sujin Suwanna and Serkan Ateş and Tobias Vogl},
url = {https://doi.org/10.1021/acsnano.3c08940},
doi = {10.1021/acsnano.3c08940},
year = {2024},
date = {2024-02-09},
journal = {ACS Nano},
abstract = {Quantum emitters in solid-state crystals have recently attracted a great deal of attention due to their simple applicability in optical quantum technologies. The polarization of single photons generated by quantum emitters is one of the key parameters that plays a crucial role in various applications, such as quantum computation, which uses the indistinguishability of photons. However, the degree of single-photon polarization is typically quantified using the time-averaged photoluminescence intensity of single emitters, which provides limited information about the dipole properties in solids. In this work, we use single defects in hexagonal boron nitride and nanodiamond as efficient room-temperature single-photon sources to reveal the origin and temporal evolution of the dipole orientation in solid-state quantum emitters. The angles of the excitation and emission dipoles relative to the crystal axes were determined experimentally and then calculated using density functional theory, which resulted in characteristic angles for every specific defect that can be used as an efficient tool for defect identification and understanding their atomic structure. Moreover, the temporal polarization dynamics revealed a strongly modified linear polarization visibility that depends on the excited-state decay time of the individual excitation. This effect can potentially be traced back to the excitation of excess charges in the local crystal environment. Understanding such hidden time-dependent mechanisms can further improve the performance of polarization-sensitive experiments, particularly that for quantum communication with single-photon emitters.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Caglar2022,
title = {Free-Space Quantum Key Distribution with Single Photons from Defects in Hexagonal Boron Nitride},
author = {Çağlar Samaner and Serkan Paçal and Görkem Mutlu and Kıvanç Uyanık and Serkan Ates},
url = {https://onlinelibrary.wiley.com/doi/10.1002/qute.202200059},
doi = {10.1002/qute.202200059},
year = {2022},
date = {2022-08-03},
journal = {Advanced Quantum Technologies},
volume = {5},
abstract = {We present a proof-of-concept demonstration of free-space quantum key distribution (QKD) with single photons generated from an isolated defect in hexagonal boron nitride (hBN). The source, operating at room temperature with a 10% brightness, is integrated into a B92 protocol and a secure key rate (SKR) of 238 bps and a quantum bit error rate (QBER) of 8.95% are achieved with 1 MHz clock rate. The effect of temporal filtering of detected photons on the performance of QKD parameters is also studied. We believe that our results will accelerate the work on improving the performance of optically active defects in hBN and their use in high-performance practical QKD systems.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}