EP-4735955-A2 - SYSTEMS AND METHODS FOR GENERATING ENTANGLED PHOTONS

EP4735955A2EP 4735955 A2EP4735955 A2EP 4735955A2EP-4735955-A2

Abstract

Systems and methods are presented for generating entangled photons. The systems and methods generally utilize dopant molecules in host materials that are contained within a micro¬ cavity. The dopant molecules are generally associated with a ground state triplet (GST) electronic manifold. When the dopant molecules are subjected to light, the electronic state of the dopant molecules is excited to an excited state triplet (EST) electronic manifold. The electronic state then decays via transition pathways that include a zero-phonon line (ZPL) electronic transition. In the presence of the micro-cavity, the decay rate along the ZPL electronic transition is greatly enhanced. Thus, the dopant molecules emit photons with a nearly pure optical state (e.g., a nearly pure wavelength and optical polarization) as they decay from the EST electronic manifold to the GST electronic manifold. As such, the optical state of the emitted photons is correlated with the electronic state of the dopant molecules.

Inventors

SCHWARTZ, Ilai
SCHAUB, Tobias

Assignees

NVision Imaging Technologies GmbH

Dates

Publication Date: 20260506
Application Date: 20240627

Claims (1)

14584.0034-00304 CLAIMS A system for generating entangled photons, the system comprising: at least one micro-cavity configured to support a material therein; at least one host material supported within the at least one micro-cavity, the host material comprising at least one organic molecule; and at least one dopant molecule contained in the host material, wherein: the at least one dopant molecule is associated with an electronic energy level structure that includes a ground state triplet (GST) electronic manifold and at least one excited state triplet (EST) electronic manifold. 2. The system of claim 1, wherein the at least one micro-cavity comprises a mode volume of at least 0.1 cubic micrometers (µm 3 ). The system of claim 1 or 2, wherein the at least one micro-cavity comprises a mode volume of at most 10 µm 3 . 4. The system of any one of claims 1-3, wherein the at least one micro-cavity is characterized by a quality (Q) factor of at least 100,000. 5. The system of any one of claims 1-4, wherein the at least one micro-cavity is characterized by a Q factor of at most 10,000,000. 6. The system of any one of claims 1-5, wherein the at least one micro-cavity is characterized by a finesse of at least 10,000. 7. The system of any one of claims 1-6, wherein the at least one micro-cavity is characterized by a finesse of at most 100,000. The system of any one of claims 1-7, wherein the at least one micro-cavity is configured to enhance radiative decay via a zero-phonon line (ZPL) electronic transition following excitation of an electronic state of the at least one dopant molecule from the GST electronic manifold to the at least one EST electronic manifold. 14584.0034-00304 9. The system of claim 8, wherein the enhanced radiative decay via the ZPL electronic transition is increased by a Purcell factor of at least 100 in comparison to a radiative decay via the ZPL electronic transition in the absence of the at least one micro-cavity. 10. The system of claim 8 or 9, wherein the enhanced radiative decay via the ZPL electronic transition is increased by a Purcell factor of at most 10,000 in comparison to a radiative decay via the ZPL electronic transition in the absence of the at least one micro-cavity. 11. The system of any one of claims 8-10, wherein the at least one dopant molecule is configured to emit at least one photon following the enhanced radioactive decay via the ZPL electronic transition. 12. The system of claim 11, wherein an optical state of the at least one photon is entangled with an electronic spin state of the at least one dopant molecule. 13. The system of claim 12, wherein the optical state comprises a polarization state of the at least one photon. 14. The system of claim 12 or 13, wherein the optical state is entangled with the electronic state by time-domain entanglement, time-domain-to-polarization entanglement, multi- photon time-domain entanglement, or multi-photon time-domain-to-polarization entanglement. 15. The system of any one of claims 1-14, wherein the host material comprises a crystalline host material, a single crystalline host material, a polycrystalline host material, a liquid crystalline host material, a powder host material, an amorphous host material, or a frozen solution host material. 16. The system of any one of claims 1-15, wherein the host material comprises a C4-C20 linear or branched alkane; an aromatic hydrocarbon; a polyaromatic hydrocarbon optionally substituted with a methylene, nitrile, carbonyl, carboxylate, alkyl, deuterated alkyl, aryl, deuterated aryl, heteroaryl, deuterated heteroaryl, borane, imine, amine, nitro, phosphine, thioether, ether, fluoro, chloro, bromo, iodo, or thiocarbonyl group; a 14584.0034-00304 diarylketone; naphthalene; anthracene; benzoic acid; fluorene; biphenyl; benzene; biphenylene; ortho-terphenyl; meta-terphenyl; para-terphenyl; di(phenyl)methanone; phenanthrene; di(naphthalen-2-yl)methanone; or any partially or fully isotopically labeled derivative thereof. 17. The system of any one of claims 1-16, wherein the host material and the at least one dopant molecule comprise a thin film having a thickness of at most 100 nanometers (nm). 18. The system of any one of claims 1-17, wherein the host material and the at least one dopant molecule are deposited on the at least one micro-cavity using spin coating or chemical vapor deposition. 19. The system of any one of claims 1-18, wherein the at least one micro-cavity is formed from a substrate selected from the group consisting of silicon, mono-crystalline silicon, polysilicon, silicon on insulator, silicon carbide, and silicon nitride. 20. The system of any one of claims 1-19, wherein the at least one dopant molecule comprises an organic molecule. 21. The system of any one of claims 1-20, wherein the at least one dopant molecule comprises a carbene molecule; a nitrene molecule; a radical molecule; a biradical molecule; a diradical molecule; a diaryl diazomethane molecule; a di(napthalen-2- yl)carbene molecule; a di(phenyl)carbene molecule; or any partially or fully isotopically labeled derivative thereof. 22. The system of any one of claims 1-21, wherein the at least one dopant molecule is contained in the at least one host material at a concentration of at most 10 6 dopant molecules per cubic micrometer (µm 3 ). 23. The system of any one of claims 1-22, further comprising at least one optical unit configured to direct light to the at least one dopant molecule to thereby excite an 14584.0034-00304 electronic state of the at least one dopant molecule from the GST electronic manifold to the at least one EST electronic manifold. 24. The system of claim 23, wherein the light comprises laser light. 25. The system of claim 24, wherein the laser light comprises a central wavelength of at least 500 nm. 26. The system of claim 24 or 25, wherein the laser light comprises a central wavelength of at most 2,000 nm. 27. The system of any one of claims 1-26, further comprising at least one electromagnetic (EM) unit configured to direct EM radiation to the at least one dopant molecule to thereby alter an electronic spin state of the at least one dopant molecule. 28. The system of claim 27, wherein the EM radiation comprises microwave (MW) radiation or radio-frequency (RF) radiation.

Description

14584.0034-00304 SYSTEMS AND METHODS FOR GENERATING ENTANGLED PHOTONS CROSS-REFERENCE [001] The present application claims priority to U.S. Provisional Patent Application No. 63/523,376, entitled “SYSTEMS AND METHODS FOR GENERATING ENTANGLED PHOTONS,” filed on June 27, 2023, and to U.S. Provisional Patent Application No. 63/552,204, entitled “SYSTEMS AND METHODS FOR GENERATING SPIN-PHOTON ENTANGLEMENT,” filed on February 12, 2024, each of which is incorporated herein by reference in its entirety for all purposes. TECHNICAL FIELD [002] The disclosed embodiments generally relate to techniques for generating entangled photons for use in non-classical communications, non-classical information processing, and/or non-classical computing, such as quantum communications, quantum information processing, and/or quantum computing. BACKGROUND [003] Non-classical information processing systems such as non-classical computers (e.g., quantum computers) typically exploit quantum mechanical phenomena, such as superposition, entanglement, and interference, to perform computational operations on data. In comparison to classical computers, which utilize binary digits (bits) that always have a defined state (0 or 1), non-classical computers utilize quantum bits (qubits) that can exist in a superposition of basis states (i.e., some linear combination of basis state |0> and basis state |1>, where basis states |0> and |1> are orthonormal). Various qubits of the non-classical computer may be entangled with other qubits (i.e., the quantum states of two or more qubits may be correlated such that operations on one qubit affect the state of an entangled qubit). Quantum operations may be 14584.0034-00304 performed to direct the states of the qubits to probabilistically converge on a particular final state, which represents the solution to some problem. For certain classes of problems, the non- classical computer may converge to the solution faster than is possible using any known algorithm on a classical computer. In some cases, this “quantum advantage” may allow the non- classical computer to solve problems that would be intractable using any known classical computer. Such problems include the factoring of large relatively prime numbers (e.g., for breaking modern cryptographic hash functions), searching for particular items in large quantities of data, and simulating the chemical behavior of drugs, materials, or other molecules. [004] Similarly, non-classical communications systems (e.g., quantum communications systems) typically exploit quantum mechanical phenomena, such as superposition, entanglement, and interference, to communicate (i.e., transmit and/or receive) information between systems located at two different locations. In comparison to classical communications systems, which transmit a series of bits that always have a defined state (0 or 1), non-classical communications systems utilize qubits that can exist in a superposition of basis states (i.e., some linear combination of basis state |0> and basis state |1>, where basis states |0> and |1> are orthonormal). While the bits of classical communications are generally unentangled (i.e., the state of one bit is not dependent on or correlated with the state of the previous bit, such that operations on one bit does not affect the state of the previous bit), in quantum communications, various qubits may be entangled with other qubits (i.e., the quantum states of two or more qubits may be correlated such that operations on one qubit affect the state of an entangled qubit). Thus, for instance, when a state of one entangled qubit is determined or otherwise manipulated (i.e., collapsed into a particular basis state), a state of a different entangled qubit may be altered (i.e., collapsed into a particular basis state). Thus, unwanted eavesdropping on the content of the information transmitted and/or received by the non-classical communications system may be immediately detected by performing operations on an entangled qubit. This general scheme 14584.0034-00304 forms the basis for numerous quantum cryptography applications which aim to create secure communications channels between different locations. [005] Numerous non-classical information processing systems and non-classical communications systems require the generation of streams of entangled photons. However, previous attempts to generate such entangled photons have generally been limited to producing small numbers of entangled photons due to materials limitations. Thus, there is a need for systems and methods that allow for the generation of large numbers of entangled photons. SUMMARY [006] The systems and methods presented herein allow for the generation of large numbers of entangled photons. The systems and methods generally utilize dopant molecules contained in host materials that are contained within at least one micro-cavity. The dopant molecules are generally associated with a ground state triplet (GST) electronic man