A U.S. Naval Analysis Laboratory (NRL) multi-disciplinary staff developed a brand new paradigm for the management of quantum emitters, offering a brand new technique for modulating and encoding quantum photonic info on a single photon gentle stream.
Quantum photonics is predicted to supply performance not attainable with classical gentle and guarantees important advances in safe communications, metrology, sensing and quantum info processing and computation.
These functions impose many necessities on quantum emitter (QE) candidates, together with deterministic creation and placement of the emitter, a excessive diploma of single photon purity starting from 90-100%, and a mechanism to regulate or modulate such emission. The flexibility to modulate the character of the sunshine emitted from these discrete emitters affords a mechanism for encoding info on a single photon stream, with functions in safe communications and quantum encryption schemes based mostly upon single photon sources. This work was just lately printed in ACS Nano.
Quantum photonics is a science and know-how that makes use of quantum optics for sure functions the place quantum results play a necessary position. It includes producing, manipulating and detecting gentle in regimes the place it’s attainable to coherently management particular person quanta of the sunshine discipline. QEs, often known as single photon emitters, are key elements on this know-how.
“Two dimensional supplies akin to monolayer tungsten disulfide and tungsten diselenide function hosts for QEs, and their planar, atomic layered construction affords many benefits as materials platforms for quantum photonic circuits,” mentioned Berend Jonker, Ph.D., NRL senior scientist and principal investigator. “They are often readily built-in with different supplies and substrates, and the proximity of the QE to the floor facilitates each extraction of the sunshine in addition to management of the emission by exterior results.”
The NRL staff developed a nonvolatile and reversible process to regulate single photon emission purity in monolayer tungsten disulfide (WS2) by integrating it with a ferroelectric materials. They create an emitter within the WS2 and are in a position to toggle the emission between excessive purity quantum gentle and semi-classical gentle by switching the ferroelectric polarization with a bias voltage. Localized emitters within the monolayer WS2 over “up-domains” within the ferroelectric movie emit excessive purity quantum gentle, whereas these over “down-domains” emit semi-classical gentle.
“This novel heterostructure introduces a brand new paradigm for management of quantum emitters by combining the nonvolatile ferroic properties of a ferroelectric with the radiative properties of the zero-dimensional atomic scale emitters embedded within the two-dimensional WS2 semiconductor monolayer,” Jonker mentioned.
The samples studied encompass monolayer movies of WS2 grown by chemical vapor deposition and mechanically transferred onto a 260-nanometer movie of an natural ferroelectric polymer, which had been beforehand transferred onto a extremely doped silicon substrate. The scientists deterministically create and place quantum emitters inside the WS2 utilizing the atomic power microscope (AFM) nanoindentation approach developed and patented by NRL.
“Reaching intimate contact between WS2 and the ferroelectric movie is essential, and requires an ultra-smooth ferroelectric movie floor,” mentioned Sungioon Lee, Ph.D., an American Society for Engineering Training (ASEE) postdoctoral fellow working with Jonker. “Due to this fact, a spin-coating and flip-over course of was used for the movie.”
“The natural ferroelectric polymer serves as a deformable polymer,” mentioned Ben Chuang, Ph.D.
analysis physicist with NRL Supplies Science and Expertise Division. “When the AFM tip is eliminated, the WS2 conforms to the contour of the nanoindent, and the native pressure discipline prompts single photon emission from atomic scale defect states within the WS2.”
For the highest electrical contact, graphite was then transferred and partially coated the WS2, and a conductive piezo power microscopy tip was used to use a bias voltage to modify the polarization of the ferroelectric polymer beneath the WS2.
Quantum emitters are elementary constructing blocks within the supplies science and quantum science applied sciences anticipated to keep up and improve warfighter dominance for the long run Navy. The Naval Science and Expertise (S&T) Technique asserts “quantum science will play an important position in naval warfare by enabling breakthrough applied sciences akin to quicker computation speeds, … sturdy encryption and progressive sensors.” The Workplace of the Undersecretary of Protection (Analysis & Engineering) and the Nationwide Protection S&T Technique 2023 have each recognized superior supplies and quantum science as crucial know-how areas.
The NRL analysis staff consisted of Sungjoon Lee, Ph.D., a postdoctoral fellow; Hsun-jen Chuang, Ph.D., analysis physicist; Kathy McCreary, Ph.D., analysis physicist; Dante O’Hara, Ph.D., supplies engineer; Berend Jonker, Ph.D., senior scientist; all the NRL Supplies S&T Division; and Andrew Yeats, Ph.D., analysis physicist with NRL Digital S&T Division.
