Signatures of Non-Markovianity in Cavity-QED with Color Centers in 2D Materials

Light-matter interactions of defects in two dimensional materials are expected to be profoundly impacted by strong coupling to phonons. In this work, we combine ab initio calculations of a defect in hBN, with a fully quantum mechanical and numerically exact description of a cavity-defect system to elucidate this impact. We show that even at weak light-matter coupling, the dynamical evolution of the cavity-defect system has clear signatures of non-markovian phonon effects, and that linear absorption spectra show the emergence of hybridised light-matter-phonon states in regimes of strong light-matter coupling. We emphasise that our methodology is general, and can be applied to a wide variety of material/defect systems.Comment: 7 pages, 3 figures + 8 pages supplemen

Exploring the phonon-assisted excitation mechanism of luminescent centres in hexagonal boron nitride by photoluminescence excitation spectroscopy

The two-dimensional material hexagonal boron nitride (hBN) hosts single-photon emitters active at room temperature. However, the microscopic origin of these emitters, as well as the mechanism through which they are excited, remain elusive. We address these issues by combining \emph{ab initio} calculations with low-temperature photoluminescence excitation spectroscopy. By studying 26 defect transitions, we find excellent qualitative agreement of experiments with the emission and absorption line shapes of the carbon trimers $\mathrm{C_2C_N}$ and $\mathrm{C_2C_B}$, while enabling us to exclude 24 defect transitions for one luminescent centre. Furthermore, we show an enhanced zero-phonon line intensity at two-phonon detuning. This unambiguously demonstrates that luminescent centers in hBN, and by inference single-photon emitters, are excited through a phonon-assisted mechanism. To the best of our knowledge, this study provides the most comprehensive insight into the excitation mechanism and the microscopic origin of luminescent centers in hBN

Signatures of non-Markovianity in cavity QED with color centers in two-dimensional materials

Light-matter interactions of defects in two-dimensional materials are expected to be profoundly impacted by strong coupling to phonons. In this work, we combine ab initio calculations of a defect in hBN with a fully quantum mechanical and numerically exact description of a cavity-defect system to elucidate this impact. We show that, even at weak light-matter coupling, the dynamical evolution of the cavity-defect system has clear signatures of non-Markovian phonon effects, and that linear absorption spectra show the emergence of hybridized light-matter-phonon states in regimes of strong light-matter coupling. We emphasise that our methodology is general, and can be applied to a wide variety of material-defect systems.</p

Jazz Innovations, Part I February 17, 2016

Concert ProgramJazz Innovations, Part 1 February 17, 201

Jazz Innovations, Part I February 17, 2016

Concert ProgramJazz Innovations, Part 1 February 17, 201

Jazz Innovations, Part I February 17, 2016

Concert ProgramJazz Innovations, Part 1 February 17, 201

Jazz Innovations, Part I February 17, 2016

Concert ProgramJazz Innovations, Part 1 February 17, 201

Jazz Innovations, Part 1 with President Bernie Fly Me to the Yoon "35" November 18, 2015

Concert ProgramJazz Innovations, Part 1 with President Bernie Fly Me to the Yoon "35" November 18, 201

Combining experiments on luminescent centres in hexagonal boron nitride with the polaron model and ab initio methods towards the identification of their microscopic origin

The two-dimensional material hexagonal boron nitride (hBN) hosts luminescent centres with emission energies of ∼2 eV which exhibit pronounced phonon sidebands. We investigate the microscopic origin of these luminescent centres by combining ab initio calculations with non-perturbative open quantum system theory to study the emission and absorption properties of 26 defect transitions. Comparing the calculated line shapes with experiments we narrow down the microscopic origin to three carbon-based defects: C2CB, C2CN, and VNCB. The theoretical method developed enables us to calculate so-called photoluminescence excitation (PLE) maps, which show excellent agreement with our experiments. The latter resolves higher-order phonon transitions, thereby confirming both the vibronic structure of the optical transition and the phonon-assisted excitation mechanism with a phonon energy ∼170 meV. We believe that the presented experiments and polaron-based method accurately describe luminescent centres in hBN and will help to identify their microscopic origin