Secure solid state quantum storage device

Abstract

The invention relates to a secure solid state quantum storage device. This disclosure describes systems and methods for producing and reading secure solid state quantum storage devices. The system includes an illumination source and a detection system. The illumination source provides excitation light to the quantum memory array. A detection system detects emitted light from the quantum memory array. The emitted light corresponds to a plurality of qubits stored in the quantum memory array.

Description

[0001] Cross - Reference to Related Applications

[0002] This application is a non - provisional patent application of U.S. Provisional Patent Application No. 63 / 621,415, entitled "SECURE SOLID - STATE QUANTUM STORAGE DEVICES", filed on January 16, 2024, which is incorporated herein by reference in its entirety. Background of the Invention

[0003] By comparing such methods with some aspects of the present methods and systems described with reference to the accompanying drawings in the remainder of the present disclosure, the limitations and disadvantages of conventional storage devices will become apparent to those skilled in the art. Summary of the Invention

[0004] Systems and methods for producing and reading secure solid - state quantum storage devices are provided, which are substantially as shown and / or described in conjunction with at least one figure and more fully set forth in the claims. Brief Description of the Drawings

[0005] Figure 1 A top view of an exemplary wafer implanted with a quantum memory array is shown in accordance with various exemplary implementations of the present disclosure.

[0006] Figure 2 A side view of an exemplary wafer implanted with a quantum memory array is shown in accordance with various exemplary implementations of the present disclosure.

[0007] Figure 3 An exemplary process flow for fabricating a quantum memory array is shown in accordance with various exemplary implementations of the present disclosure.

[0008] Figure 4 An example of ion implantation in a quantum memory array is shown in accordance with various exemplary implementations of the present disclosure.

[0009] Figure 5 An exemplary quantum memory array readout system having a micro - LED illuminator array and a 2D imager is shown in accordance with various exemplary implementations of the present disclosure.

[0010] Figure 6 An exemplary quantum memory array readout system having a holographic excitation source is shown in accordance with various exemplary implementations of the present disclosure.

[0011] Figure 7 An exemplary quantum memory array readout system having front illumination and back illumination and a 3D holographic position mapper is shown in accordance with various exemplary implementations of the present disclosure.

[0012] Figure 8 Details of an exemplary security decoder according to various exemplary implementations of the present disclosure are shown. DETAILED DESCRIPTION

[0013] The present disclosure describes processes for artificially generating and detecting defects in a substrate. These processes enable encoding, storing, and decoding of data via a quantum memory array. The generation of defects is achieved by high-energy ion implantation or high-power focused short optical pulses. The quantum memory can employ ultra-wide bandgap semiconductors (UWBGS), such as silicon carbide (SiC), gallium nitride (GaN), gallium oxide (GaO), boron nitride (BN), or diamond.

[0014] The quantum memory utilizes color centers (atomic point defects in UWBGS materials) to store stable quantum states, even in harsh environments. Compared to other materials, SiC has advantages such as larger wafer sizes and lower intrinsic defect densities.

[0015] The disclosed quantum memory system encodes information to enable secure, high-density storage. Quantum bits are embedded in predefined color centers arranged in a 2D grid with multiple depth levels, facilitating advanced coding methods.

[0016] The quantum memory array can be integrated with a quantum computing system, where the quantum memory array includes multiple quantum color centers aligned with a quantum bit processor.

[0017] Figure 1 and Figure 2 Depicts the structure of a UWBGS wafer and the arrangement of quantum bits in a multi-level grid. These figures provide insights into the material properties and coding configurations. Figure 1 A top view of a wafer with a 2D quantum memory array is shown. Figure 2 A side view is provided, showing the depth-level coding within the array.

[0018] Encoding

[0019] Figure 3 An exemplary process flow for fabricating a quantum memory array according to various exemplary implementations of the present disclosure is shown. Such a wafer-level fabrication process can achieve high areal density quantum storage through secure coding and printing.

[0020] Figure 3 Also includes examples of ion implantation processes, highlighting the role of photomasks, specific depth implantation, and annealing processes. The write process can also utilize a high-power pulsed laser with programmable depth focus in a wafer with or without a photomask. These figures emphasize the precision required for encoding.

[0021] The wafer can be SiC, diamond, or other similar materials. At 301, an optical metal mask is deposited on the wafer. The mask provides a spatial distribution such as Figure 1 shown. The mask is depicted with encoded, secure information. Multiple pattern masks can be used to transfer information at different depths into the memory array.

[0022] At 303, ions are implanted into the wafer to generate detectable defects. Helium (He) can be used for implantation into SiC. Other ions such as hydrogen (H+) and nitrogen (N+), or atomic color center impurities such as vanadium (Va) can also be used, depending on the desired defect structure and properties of the resulting color center.

[0023] Different ion energy levels can generate different levels of defects. Each iteration of 303 uses a different energy to provide depth coordinates such as Figure 2 shown. For example, 303 can be repeated to generate a layer-by-layer construction of N layers of pixels. On the Figure 3 right, an example of the ion implantation process is shown for N = 3. These pixels can be data-encoded qubits associated with a security key. Through the ion implantation process, defects can be generated simultaneously at multiple locations across the wafer in both the x-dimension and the y-dimension. Multiple masks can be generated and aligned with sub-micron resolution to each other to achieve ultra-high aerial density. Multistage implantation with different ion implantation energies can be used to generate defects at predetermined locations and depths. A combination of multiple mask implantations can provide gray-scale coding at specified area locations.

[0024] At 305, the mask is removed from the implanted wafer. After N iterations of 301, 303, and 305, annealing at 307 finally completes the multilevel quantum memory, solidifying the encoded data.

[0025] Secure coding is achieved by encrypting the data within the storage pixels and distributing the bits across multiple depths and locations. Advanced coding processes can be used to scatter the binary data into an encrypted format.

[0026] Additional methods such as high-energy radiation or impurity implantation can enhance the generation of color centers. Parameters such as ion energy and ion dose can affect the depth, emission brightness, and emission wavelength of the specified color center, thus ensuring high stability and resistance to external interference. The following table provides exemplary ion implantation energies and doses that can be used with He ions:

[0027]

[0028] Table 1 Exemplary ion implantation energies and doses

[0029] The implantation process results in a damage profile that spreads laterally. Pixel placement can be determined by ion energy and dose to ensure sufficient separation to avoid signal overlap.

[0030] Figure 4 Examples of the lateral depth, lateral spread, and lateral straggle distribution of He ion implantation in a quantum memory array according to various exemplary implementations of the present disclosure are shown. Figure 4 An energy level of 50 keV and a dose of 1×10 14 / cm 2 are presented.

[0031] When ions are implanted into a crystal, they slow down until they reach a specific depth and then stop, creating a damage curve similar to a Gaussian curve.

[0032] At the high-intensity peak, the dose can spread, for example, in the range of 1000 to 3000 angstroms. The movement of ions parallel to the wafer surface due to ion implantation is shown by the lateral straggle distribution curve. The lateral depth and lateral spread curves represent other depths.

[0033] Although there may be a trailing effect for adjacent pixels, the slight difference in intensity enables the use of advanced encoding and decoding techniques to recover information. However, the maximum feature density may be limited by lateral spread, which depends on ion energy. For example, this may result in an area of 100 nanometers for each straggle distribution, and the pitch between two features is approximately 200 nanometers. This pitch can define the maximum density of the imprint and enables the reading of color centers with a high level of precision.

[0034] In addition to the precision and accuracy achievable via ion implantation, the present disclosure is also capable of achieving tamper resistance through encryption techniques. Encryption does not simply form color centers for each data bit, but spreads the data across multiple locations and depths.

[0035] For example, when preparing a photomask, the original binary data (such as "0" or "1") can be encrypted using a key to scramble or stretch the data bits and distribute them across various locations, depths, and colors. This ensures that only authorized users with the correct detection color filter and decryption key can access and reconstruct the data, thereby enhancing security and robustness in quantum memory applications.

[0036] An encoder can encrypt incoming data, generate a spatially encoded implantation mask, and control the corresponding energy and dose of an ion implanter. When implanting different color center impurities, specific wavelengths of excitation light and associated detection color filters may be required to excite and observe the specified quantum transitions. The encoded data can be transferred and printed onto a photomask. The pattern of the photomask can be transferred and delineated into a hard implantation mask on the surface of a semiconductor substrate, where the implantation mask can allow ions or pulsed lasers to pass through open pixel positions to form color centers while blocking non-storage areas. Different masks can overlap each other to provide different implantation depths at different positions.

[0037] Decoding

[0038] Decoding a quantum memory relies on optical excitation to retrieve data from multiple color centers. Excitation at a specific wavelength triggers light emission, enabling the stored information to be read out. The luminescence rate of the color centers can be less than ten nanoseconds, allowing for rapid data retrieval. A detection system can be configured to detect the emitted light from pixels of a quantum memory array, and the emitted light can be decoded into multiple qubits.

[0039] Figure 5 An exemplary quantum memory array readout system with a micro-LED illuminator array and a 2D imager according to various exemplary implementations of the present disclosure is shown. The wavelength of the illumination source can excite the color centers from the ground state to the excited quantum state. The wavelengths of the color filter and the detector can detect the unique emitted light of the specified color centers. For example, the implanted He in SiC color centers written can be read out using excitation light at 781 nm and a detector from 940 nm to 950 nm. Figure 6 An exemplary quantum memory array readout system with a holographic excitation source according to various exemplary implementations of the present disclosure is shown. Figure 7 An exemplary quantum memory array readout system with front illumination and back illumination and a 3D holographic position mapper according to various exemplary implementations of the present disclosure is shown.

[0040] Figures 5 to 7 Each of the readout systems in [FIGURE REFERENCE] shows a quantum memory wafer 501. Figures 5 to 7 Each of the readout systems in [FIGURE REFERENCE] includes a unique illumination source (described in more detail below with respect to each figure), a lens 503, an imager 505, a security decoder 507, and a security key 509. Figure 8 Details of an exemplary security decoder 507 according to various exemplary implementations of the present disclosure are shown. To enhance security and storage density, multiple types of color centers can be written into the wafer. Detection of multiple types of color centers may require different excitation light sources, color filters, and / or detectors to read out the data stored in each type of color center and assemble and compile the information together.

[0041] Figures 5 to 7 The readout system in Figures 5 to 7 can use serial scanning to pick up the excited qubits. The serial scanning can include a sequential read head to address each memory pixel (one by one), similar to a CD ROM, with a synchronously rotating mechanical substrate to read out the bits stored in the x-y dimension.

[0042] A lens 503 and an imager 505 (e.g., a CMOS camera) can be used to record the emitted light of the memory array in the focused area. The security decoder 507 can use direct 2D security readout or digital 3D holographic security readout. With direct 2D security readout, the security decoder 507 can use the security key 509 to decode the intensity of the 2D emitted light from the x-y array, as Figure 8 shown.

[0043] With digital 3D holographic security readout, the security decoder 507 can first retrieve the information stored holographically in 3D from 2D positions with corresponding intensities. The security decoder 507 can then map the data into 3D defect positions. The time-secure position-encoded data can be decoded into the original information using the security key 509. This allows encoding and decoding of security information via spatially distributed programmed defects at various x-y and depth positions.

[0044] The illumination source can be configured to provide excitation light to the quantum memory array of the quantum memory wafer 501. The illumination source can be, for example, a laser, a light-emitting diode (LED), or a micro-LED array. The illumination source can be a pulsed source or a continuous-wave (CW) source.

[0045] In Figure 5 , the illumination source includes a micro-LED array 511 and a programmable security element 513, such as one or more keys or watermarks.

[0046] In Figure 6 , the illumination source includes a laser 601, a programmable diffractive optical device 603, and a programmable security element 605. The programmable diffractive optical device 603 can be configured to project a 3D holographic key and / or watermark via the programmable security element 605 that can excite 3D color centers (e.g., at different depths).

[0047] The programmable diffractive optical device 603 can include a planar multi-layer optical waveguide having multiple layers. The planar multi-layer optical waveguide can be configured to guide the excitation light and collect the emitted light. The planar multi-layer optical waveguide can also be directly deposited on the quantum memory array 501.

[0048] In Figure 7, the illumination source includes a backside illumination light source (or source array) 701 and a frontside illumination light source (or source array) 703 to provide energy above and below the wafer 501. The excitation light can be a constant wave (CW) with or without coded pulses. The illumination can be provided to the front side 703 or back side 701 of the substrate or to the edge with a distributed waveguide. The illumination source (701 and / or 703) can include a 2D addressable micro-LED or a laser array that matches the memory pixel layout. Pixels can be illuminated one by one or multiple pixels at a time. A single illumination source (701 and / or 703) can be split into two or more beams.

[0049] The emitted light from the written 3D quantum defects can be detected by the intensity-based digital holographic position mapper 705. The digital holographic position mapper 705 can store the xy position and intensity of the detected light in a data buffer.

[0050] The readout process can occur serially or in parallel using an imaging array. High-performance CMOS imagers can, for example, operate at 100 million frames per second and achieve readout rates of up to 1 petabit per second. Parallel detection and optimized decoder electronics can increase the overall readout rate, alleviating potential speed limitations.

[0051] Quantum memory systems can be designed primarily for read-only purposes, with decay times ranging from nanoseconds to microseconds. These properties ensure reliable data retrieval with minimal decay-related problems. Coding overhead may reduce readout rates slightly, but the high-speed capabilities of quantum memory remain unmatched.

[0052] The maximum memory density depends on the size of each pixel. The physical size of each pixel may be limited by the size of the lithography process for the implantation mask and the lateral scattering (diffusion) of the implanted ions (e.g., 100 nm at 50 keV), which can yield a pixel size of approximately 0.35 microns by 0.35 microns. By applying error correction codes, the pixel size can be further reduced to, for example, 0.2 microns by 0.2 microns.

[0053] Planar multilayer optical waveguide layers can be deposited on the wafer in the xy plane. Grating couplers can be incorporated at the waveguide intersections to inject and read out light vertically. Each pixel can be individually addressed by optical switches at the input of the x- and y-waveguides. A 2D liquid crystal on silicon (LCOS) switch with individually addressable pixels can be used to selectively read out light from the corresponding memory bit in the array.

[0054] Prior to detection and decoding, the light intensity and holographic pattern can be calibrated and self-adjusted to a set of prescribed encoding patterns on the wafer.

[0055] For sequential reading and decoding of sequentially encoded information, security can be embedded and spread over several consecutive bits. A sequential reading system can read and capture the read bits of a desired length before decoding. This can be provided by incorporating several overhead bits for error-correcting coding.

[0056] By aligning a micro-LED array with a quantum color center storage array, a pixel-specific turn-on pattern of the 2D micro-LED array can accumulate intensities from overlapping 3D color centers. A holographic emitter can illuminate the 3D color center array and excite individually addressed pixels at a specified depth to access depth information. A tunable excitation light source, a color filter, and a broadband detector can extract information stored between hybrid types of color centers.

[0057] The detection system can be configured to resolve the wavelength and / or polarization of the emitted light. The detection system can be configured to resolve the overlapping signals of the emitted light according to a machine learning algorithm.

[0058] The detection system can include an optical isolator or a diffusive encoder to mitigate signal overlap between adjacent pixels. The optical isolator or encoder can include a multi-layer interference filter and / or a spatial light modulator to dynamically adjust the emitted light density and position.

[0059] The detection system can include a data reconstruction module calibrated for pixel intensity variations caused by differences in injection depth. The various frequency components of the emitted light from different types of color centers can be aggregated and decrypted through data processing. Nonlinearities in the emitted light signal can be compensated using polynomial regression.

[0060] The reading system described herein can operate at room temperature. When integrated with a qubit quantum detector, a cooled photodetector can also be used.

[0061] Although the method and / or system have been described with reference to certain implementations, those skilled in the art will understand that various changes can be made and equivalents can be substituted without departing from the scope of the method and / or system. Additionally, many modifications can be made to adapt a particular situation or material to the teachings of the disclosure without departing from its scope. Therefore, the method and / or system are not intended to be limited to the particular implementations disclosed, but rather the method and / or system will include all implementations falling within the scope of the appended claims.

Claims

1. A system, the system comprising: a lighting source configured to provide excitation light to a quantum memory array; and a detection system configured to detect emitted light from the quantum memory array, wherein the emitted light corresponds to a plurality of qubits stored in the quantum memory array.

2. The system according to claim 1, wherein: the quantum memory array includes a plurality of pixels, and each pixel of the plurality of pixels is associated with a pixel size determined according to ion implantation energy and ion dose.

3. The system according to claim 1, wherein: the excitation light includes one or more wavelengths, and each of the one or more wavelengths corresponds to a different type of color center.

4. The system according to claim 1, wherein The lighting source is one of a laser, a light emitting diode (LED), and a micro-LED array.

5. The system according to claim 1, wherein The lighting source is one of a pulsed source and a continuous wave source.

6. The system according to claim 1, wherein: the lighting source is configured to provide the excitation light under a transparent substrate.

7. The system according to claim 1, wherein: the system includes a planar multi-layer optical waveguide, the planar multi-layer optical waveguide including a plurality of layers deposited on the quantum memory array, and the planar multi-layer optical waveguide is configured to guide the excitation light and collect the emitted light.

8. The system according to claim 1, wherein: the excitation light corresponds to a watermark.

9. The system according to claim 1, wherein: the detection system includes a security decoder, the plurality of qubits are scrambled by diffusion across the quantum memory array, and the security decoder is configured to decode the plurality of qubits according to the spatial distribution and intensity of the emitted light based on one or more encryption keys.

10. The system according to claim 9, wherein: the security decoder is configured according to one or both of 2D readout and 3D holographic readout.

11. The system according to claim 1, wherein: the quantum memory array includes a plurality of pixels, and each pixel of the plurality of pixels is associated with a pixel size determined according to the intensity and focal depth of a high energy pulsed laser.

12. The system according to claim 1, wherein: the detection system includes one or both of a 2D imager and a CMOS camera.

13. The system according to claim 1, wherein: the detection system is configured to resolve one or both of the wavelength and polarization of the emitted light.

14. The system according to claim 1, wherein: the detection system is configured to resolve the overlapping signal and / or scrambled signal of the emitted light according to a machine learning algorithm.

15. The system according to claim 14, wherein: the machine learning algorithm is configured according to a security key.

16. The system according to claim 1, wherein: the quantum memory array includes a plurality of pixels, and the detection system includes an optical isolator configured to mitigate signal overlap associated with adjacent pixels among the plurality of pixels.

17. The system according to claim 16, wherein: The optical isolator includes an encoder having a spatial light modulator configured to dynamically adjust the emitted light.

18. The system according to claim 16, wherein: The optical isolator includes a multilayer interference filter.

19. The system according to claim 1, wherein: The quantum memory array includes a plurality of pixels, and The detection system includes a data reconstruction module calibrated for changes in pixel intensity and wavelength.

20. The system according to claim 1, wherein: The detection system is configured to use polynomial regression to correct for non-linearity in the emitted optical signal.

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