DOI: 10.21950/oszvzo
title: Temporal coherence of single photons emitted by hexagonal Boron Nitride defects at room temperature

description: &lt;p&gt;Color centers in hexagonal boron nitride (hBN) emerge as promising quantum light
sources at room temperature, with potential applications in quantum communications,
among others. The temporal coherence of emitted photons (i.e. their capacity to inter-
fere and distribute photonic entanglement) is essential for many of these applications.
Hence, it is crucial to study and determine the temporal coherence of this emission un-
der different experimental conditions. In this work, we report the coherence time of the
single photons emitted by an hBN defect in a nanocrystal at room temperature, mea-
sured via Michelson interferometry. The visibility of this interference vanishes when
the temporal delay between the interferometer arms is a few hundred femtoseconds,
highlighting that the phonon dephasing processes are four orders of magnitude faster
than the spontaneous decay time of the emitter. We also analyze the single photon
characteristics of the emission via correlation measurements, defect blinking dynamics,
and its Debye-Waller factor. Our room temperature results highlight the presence of a
strong electron-phonon coupling, suggesting the need to work at cryogenic temperatures
to enable quantum photonic applications based on photon interference.&lt;/p&gt;

&lt;p&gt;This dataset includes data from the experiments carried out to investigate the temporal coherence of hBN at room temperature, including photoluminescence (PL) spectra of several hBN emitters under different excitation conditions, time-resolved fluorescence decay, second-order correlation measurements, and Michelson interferometry of single photons. This data has been used to generae the figures included in the publication: "Temporal coherence of single photons emitted by hexagonal Boron Nitride defects at room temperature".&lt;/p&gt;


&lt;p&gt;1- "Basic Characterization": Data for the basic characterization of an hBN emitter at room temperature. Contains three subfolders:&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;PL spectrum&lt;/li&gt;
&lt;li&gt;Saturation Curve&lt;/li&gt;
&lt;li&gt;Spontaneous decay (T1)&lt;/li&gt;
&lt;/ul&gt;
&lt;/p&gt;2- "Second order correlation function": Includes data for the second-order correlation function (obtained via the Hanbury-Brown and Twiss experiment) of the same hBN emitter under different excitation powers with pulsed and continuous wave driving. Its is divided in the following subfolders:&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;G2 CW&lt;/li&gt;
&lt;li&gt;G2 Pulsed&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;3- "Michelson interferometry of an emitter": Includes data for the Michelson fringes (for different path delays) for the emisión of the same hBN emitter considering two filtering regions (ZPL and full spectrum). It is divided in the subfolders:&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;Full spectrum&lt;/li&gt;
&lt;li&gt;ZPL&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;4-"Michelson interferometry under different excitation conditions": Contains data of three hBN emitters (different from the one characterized in the rest of the dataset) excited with different laser wavelengths. This folder contains data of the PL spectra (for different excitation color) and the corresponding Michelson fringes (for different path delays). This folder is organized as follows:&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;Emitter I&lt;/li&gt;
&lt;ul&gt;
&lt;li&gt;Michelson Blue&lt;/li&gt;
&lt;li&gt;Michelson Green&lt;/li&gt;
&lt;li&gt;PL spectra&lt;/li&gt;
&lt;/ul&gt;
&lt;/ul&gt;

&lt;ul&gt;
&lt;li&gt;Emitter II&lt;/li&gt;
&lt;ul&gt;
&lt;li&gt;Michelson Blue&lt;/li&gt;
&lt;li&gt;Michelson Green&lt;/li&gt;
&lt;li&gt;PL spectra&lt;/li&gt;
&lt;/ul&gt;
&lt;/ul&gt;

&lt;ul&gt;
&lt;li&gt;Emitter III&lt;/li&gt;
&lt;ul&gt;
&lt;li&gt;Michelson Blue&lt;/li&gt;
&lt;li&gt;Michelson Red&lt;/li&gt;
&lt;li&gt;PL spectra&lt;/li&gt;
&lt;/ul&gt;
&lt;/ul&gt;
&lt;p&gt;Data from second-order correlation measurements and Michelson interferometry have been generated by the software Extensible Timetag Analyzer (https://timetag.github.io/).&lt;/p&gt;
description: Methodology

Photoluminescence spectroscopy
Time-resolved fluorescence spectroscopy
Time-correlated single photon counting
Michelson interferometry

 Data from second-order correlation measurements and Michelson interferometry have been generated by the software Extensible Timetag Analyzer (https://timetag.github.io/).
description: Extensible Timetag Analyzer