Highly Reproducible Monochromatic Quantum Emitters in Hexagonal Boron Nitride

Muchuan Hua
Argonne National Laboratory, Lemont, Illinois, USA _______________________________________

Highly quality single photon sources are essential components for optical quantum information science and technology, especially for quantum computation. Quantum emitters (QE) in 2D materials are potential candidates who have the advantage that can be seamlessly integrated into semiconducting circuits. Recently, we developed a platform, Quantum Emitter Electron Nanomaterial Microscope (QuEEN-M), for studying atomic structures and optical properties of quantum emitters at high spatiotemporal resolution, by combining atomic resolution scanning transmission electron microscopy, cathodoluminescence, electrostatic beam blanker (nanosecond pulser), and an ultrafast pulser (picosecond pulser). Using the QuEEN-M, we achieved sub-10nm spatial resolution CL imaging of individual QEs in hexagonal boron nitride (hBN) with sub-nm localization precision. With this high precision, we revealed the atomic structures of 440 nm blue emitters in hBN as a vertical carbon dimer at either N or B sites. With the atomic structure insights, we utilized carbon ion implantation on thin hBN flakes, yielding room temperature monochromatic QEs in hBN with perfect reproducibility. These QEs share almost identical narrow emission line profile (emission center wavelength = 590.7 ± 2.7 nm and a full width half maximum = 7.1 ±1.7 nm) with excellent brightness, making them perfect candidates for optical quantum applications. Meanwhile, we were able to obtain the induced carbon defects’ atomic resolution STEM images and correlated them to observed single photon emission.

Email: mhua@anl.gov