Deterministic Quantum Emitter Formation in Hexagonal Boron Nitride via Controlled Edge Creation



Technology Background:  Sources of single photons are a key component of many emerging quantum information technologies such as quantum computation, communication, and sensing. However, the more commonly used quantum emitters (QEs), such as cold atoms and spontaneous parametric down-conversion sources, require complex setups that limit their viability for widespread use. In contrast, solid-state QEs require significantly simpler setups because they can operate in ambient conditions. In addition, they have the possibility of high quantum efficiency and integrability with on-chip devices.

Definition of Problem: Ultrabright and stable QEs have been observed to occur stochastically at edges or regions of high curvature in hexagonal boron nitride (hBN), a large-bandgap 2D material. However, no method exists for deterministically and reliably fabricating QEs in hBN at desired locations in a manner suitable for integration with hybrid quantum devices.

Our Technology Solution:  University of Oregon researchers have discovered a method to deterministically create QEs at controlled locations in hBN. QEs are fabricated by creating edges having specific characteristics, e.g., using patterned milling of holes in hBN using a gallium focused ion beam (FIB). Through the use of specific milling and annealing parameters, a 31% yield of single QEs was achieved. The QEs form best and with preferably properties through uniform milling of smooth holes on relatively smooth chemical vapor deposition (CVD) hBN. The result is a fabricated QE nanoscale device (or an array of devices) with specific size and shape characteristics. Optical confocal microscopy confirmed that such an array exhibits an array of bright, localized photoluminescence that match the geometry of the patterned holes. Second-order photon correlation measurements on these bright spots confirm that they contain single and multiple QEs. This technique dramatically broadens the utility and convenience of hBN QEs and achieves a vital step toward the facile integration of the QEs into large-scale photonic, plasmonic, nanomechanical, or optoelectronic devices.

Applications: Single-photon quantum emitters are in high demand for many emerging quantum information technologies such as quantum computation, communication, and sensing.

US Patent # 10,879,445

Patent Information:
For Information, Contact:
Jim Deane
University of Oregon
Benjamin Aleman