US-20260130011-A1 - METHODS OF PRODUCING SINGLE PHOTON EMITTERS ON SUBSTRATES, AND DEVICES, AND CHIPS

US20260130011A1US 20260130011 A1US20260130011 A1US 20260130011A1US-20260130011-A1

Abstract

Methods of fabricating single photon emitters (SPEs) including nanoindentation of hexagonal boron nitride (hBN) host materials and annealing thereof, devices formed from such methods, and chips with a single photon emitter. A substrate with a layer of hBN is provided. Nanoindentation is performed on the layer of hBN to produce an array of sub-micron indentations in the layer of hBN. The layer of hBN is annealed to activate SPEs near the indentations. Devices include a substrate with an SPE produced in accordance with the methods. Chips include a substrate, an hBN layer, and an SPE including an indentation on the hBN layer, in which the substrate is not damaged at the indentation.

Inventors

Xiaohui XU
Zachariah Olson Martin
Demid Sychev
ALEXEI S. LAGUTCHEV
Yong Chen
Vladimir Michael Shalaev
Alexandra Boltasseva

Assignees

PURDUE RESEARCH FOUNDATION

Dates

Publication Date: 20260507
Application Date: 20260105

Claims (3)

1 . A chip comprising: a substrate; an hBN layer disposed on the substrate; and a single photon emitter (SPE) comprising an indentation in the hBN layer; wherein the substrate is not damaged at the indentation.
2 . The chip of claim 1 , wherein the indentation comprises a dip in the hBN layer and a bent hBN piece immediately adjacent the dip.
3 . The chip of claim 1 , the chip comprising a plurality of the SPEs in the hBN layer, wherein the indentations of the plurality of SPEs are disposed in an array across the substrate and the hBN layer, and wherein the array is a non-random pattern.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This is a division patent application of co-pending U.S. patent application Ser. No. 17/845,093 filed Jun. 21, 2022, which claims priority to provisional U.S. Patent Application No. 63/212,924, filed Jun. 21, 2021. The contents of these prior applications are incorporated herein by reference. STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH OR DEVELOPMENT This invention was made with government support under 2015025-ECCS awarded by National Science Foundation and DE-AC05-00OR22725 awarded by the Department of Energy. The government has certain rights in the invention. BACKGROUND OF THE INVENTION The present invention generally relates to single photon emitters (SPEs). The invention particularly relates to methods of fabricating SPEs including nanoindentation of hexagonal boron nitride (hBN) host materials and annealing thereof, devices formed from the methods, and a chip with a single photon emitter. Solid-state SPEs are receiving increasing attention in the last decade due to their critical role in quantum information technologies including quantum computing, secure quantum communication, etc. Such SPEs are typically composed of atomic defect structures in a solid-state host material that are suitable for integrated quantum photonic systems. Recently, two-dimensional (2D) van der Waals materials such as transition-metal dichalcogenides (TMDCs) and hexagonal boron nitride (hBN) have been extensively investigated due to their capability to host SPEs. For instance, various types of SPEs operating at ambient conditions have been identified in hBN, with emission ranging from ultra-violet (UV) to the near infra-red (NIR) spectral regime. The atomic-scale thickness of 2D hBN not only enables high-efficiency light extraction, but also offers unparalleled advantages for integrating SPEs with plasmonic and photonic structures for hybrid quantum devices. The practical integration of SPEs in 2D materials requires deterministic creation or activation of emitters at designated locations. Recent studies have reported a few methods to fabricate position-controlled SPEs in 2D materials based on strain engineering, ion/electron beam irradiation and controlled bottom-up growth. Strain/curvature-induced SPEs in hBN and TMDCs have been fabricated either by employing a nano-structured substrate (e.g., with nanopillars, nanocones, etc.), or by deforming the 2D materials into a soft polymetric substrate. However, both approaches have limited applications in quantum integrated photonics due to the involvement of patterned substrates or polymers. A similar strategy was utilized in a recent work to obtain SPEs that are not purely strain-induced in hBN, by growing hBN on dielectric nanopillars using chemical vapor deposition (CVD). Aside from the above-mentioned methods, gallium focused ion beam (FIB) and electron beam have been demonstrated to create position-controlled SPEs in hBN flakes on a flat substrate. However, the fluorescence contamination induced by high-energy gallium ion implantation could be a potential concern in practice, and SPE activation by electron beam suffers from limited spatial precision (larger than 1 μm). Therefore, the above-noted techniques are limited in that they either rely on a patterned substrate that is not compatible with integrated photonic devices or utilize a radiation source that might cause unpredictable damage on hBN and underlying substrates. In view of the above, it can be appreciated that there are certain problems, shortcomings or disadvantages associated with SPE fabrication techniques, and that it would be desirable if methods were available for producing SPEs on chip-compatible substrates that were capable of at least partly overcoming or avoiding the problems, shortcomings or disadvantages noted above. BRIEF DESCRIPTION OF THE INVENTION The present invention provides methods of producing SPEs on chip-compatible substrates, devices formed by such methods, and chips with one or more SPEs. According to one nonlimiting aspect of the invention, a method is provided for producing single photon emitters (SPEs) on a substrate. The method includes providing a substrate having a layer of hexagonal boron nitride (hBN) thereon, performing nanoindentation of the layer of hBN to produce an array of sub-micron indentations in the layer of hBN on the substrate, and annealing the layer of hBN having the sub-micron indentations thereon to activate single-photon emitters (SPEs) near the indentations. According to other nonlimiting aspects, the method optionally includes one or more variations and/or features, including but not limited to: the substrate may include an SiO2-coated Si substrate; the layer of hBN may include one or more hBN flakes; the hBN flakes may be flexible in terms of thickness; the method may include producing the substrate by depositing exfoliated hBN flakes on a non-patterned, planar surface of a SiO2-coated silicon substrate; the SPEs may emi