title: Temperature Dependence of Wavelength Selectable Zero-Phonon Emission from Single Defects in Hexagonal Boron Nitride.
abstract: We investigate the distribution and temperature-dependent optical properties of sharp, zero-phonon emission from defect-based single photon sources in multilayer hexagonal boron nitride (h-BN) flakes. We observe sharp emission lines from optically active defects distributed across an energy range that exceeds 500 meV. Spectrally resolved photon-correlation measurements verify single photon emission, even when multiple emission lines are simultaneously excited within the same h-BN flake. We also present a detailed study of the temperature-dependent line width, spectral energy shift, and intensity for two different zero-phonon lines centered at 575 and 682 nm, which reveals a nearly identical temperature dependence despite a large difference in transition energy. Our temperature-dependent results are well described by a lattice vibration model that considers piezoelectric coupling to in-plane phonons. Finally, polarization spectroscopy measurements suggest that whereas the 575 nm emission line is directly excited by 532 nm excitation, the 682 nm line is excited indirectly.
authors: Cornell University , Ithaca, New York 14853, United States.
authors: Nicholas R
authors: NR
authors: Jungwirth
authors: Cornell University , Ithaca, New York 14853, United States.
authors: Brian
authors: B
authors: Calderon
authors: Cornell University , Ithaca, New York 14853, United States.
authors: Yanxin
authors: Y
authors: Ji
authors: Cornell University , Ithaca, New York 14853, United States.
authors: Michael G
authors: MG
authors: Spencer
authors: University of Iowa , Iowa City, Iowa 52242, United States.
authors: Michael E
authors: ME
authors: Flatté
authors: Cornell University , Ithaca, New York 14853, United States.
authors: Gregory D
authors: GD
authors: Fuchs
keywords: 2D material; Single-photon source; hexagonal boron nitride; line width; point defect; zero-phonon line