A macroscopic quantum state transmission device based on a distorted double-layer graphene moire superlattice and an implementation method thereof

Abstract

The application discloses a macro quantum state transmission device based on a twisted double-layer graphene moire superlattice and an implementation method thereof. The device comprises a sending end and a receiving end twisted double-layer graphene moire superlattice element (twist angle, with a non-zero topological Chern number), a gate voltage regulation system (continuous regulation), a projection angle modulation system, a synchronous control system and a quantum state reading system. The device synchronously modulates the projection angle of the sending end and the receiving end to a critical value through the gate voltage, and realizes the instantaneous transmission of the macro quantum state. The transmission fidelity. The application utilizes the gate-adjustable topological Chern number of the twisted double-layer graphene moire superlattice, realizes the macro quantum state transmission working at room temperature, has low power consumption, and is suitable for scenarios such as interstellar communication and quantum network.

Description

Technical Field

[0001] This invention relates to the fields of quantum information transmission technology and two-dimensional materials technology, specifically to a macroscopic quantum state transmission device and its implementation method based on a twisted bilayer graphene moiré superlattice. This invention can be applied to fields such as macroscopic quantum state transmission, interstellar communication, quantum network node interconnection, remote quantum computing collaboration, and quantum-enhanced navigation systems, and is particularly suitable for applications that achieve high-fidelity, tunable macroscopic quantum state transmission based on a two-dimensional material moiré superlattice platform. Background Technology

[0002] Macroscopic quantum state transmission technology synchronously drives the topological materials of the transmitter and receiver to a critical state. This enables the instantaneous transmission of quantum states of macroscopic objects. The selection of topological material components is a key factor determining the transmission fidelity and engineering feasibility. Twisted bilayer graphene (TBG) represents a major breakthrough in the field of two-dimensional materials in recent years. When two layers of graphene are stacked at a specific "magic angle" (approximately 1.1°), interference effects caused by interlayer coupling and lattice mismatch result in a long-period moiré superlattice with a flat topological band structure. The carrier density can be altered by adjusting the gate voltage. and vertical electric field The topological Chern number of moiré superlattices can be precisely controlled. Magic-angle twisted bilayer graphene has been experimentally proven to have a non-zero topological Chern number. Furthermore, its topological properties are highly tunable by an external electric field. However, current applications of twisted bilayer graphene are mainly concentrated in fundamental research in condensed matter physics and electronic devices, and it has not yet been used for macroscopic quantum state transport. Its application in macroscopic quantum state transport faces the following technical challenges: (i) Lack of macroscopic quantum state transport architecture based on twisted bilayer graphene Existing macroscopic quantum state transport schemes primarily employ magnetic topological insulators (such as MnBi₂Te₄) as topological material elements. Twisted bilayer graphene moiré superlattices possess unique topological tunability (the Chern number can be continuously adjusted via gate voltage). However, it has not yet been integrated into macroscopic quantum state transmission devices. (II) The Co-optimization Problem of Topological Chern Number Regulation and Macroscopic Transport in Twisted Bilayer Graphene Topological Chern number of twisted bilayer graphene With gate voltage and twist angle The process involves continuous change and multiple topological phase transition points. Therefore, it is necessary to establish a topological Chern number. With macroscopic quantum state transmission fidelity The quantitative relationship between them is used to achieve synergistic optimization. (III) The problem of coherent coupling between moiré superlattices and macroscopic objects Macroscopic objects (including) (Each particle) needs to form a strong coherent coupling with the topological surface states of the twisted bilayer graphene moiré superlattice. The local state density distribution and spatial positions of the topological boundary states of the moiré superlattice need to be optimized by overlapping with the wave function of the macroscopic object. (iv) Lack of room temperature working schemes based on two-dimensional material platforms Existing MnBi2Te4 solutions require low-temperature operation. This limitation restricts its engineering applications. Twisted bilayer graphene, with its higher intrinsic bandgap and topological stability, holds promise for operation at room temperature or higher. To address the aforementioned problems, this invention provides a macroscopic quantum state transport device and its implementation method based on a twisted bilayer graphene moiré superlattice. Summary of the Invention

[0003] (a) Purpose of the invention This invention aims to address the technical problems in existing macroscopic quantum state transmission technologies, such as the lack of a transmission architecture based on twisted bilayer graphene, the lack of synergistic optimization between topological Chern number control and macroscopic transmission, the difficulty of coherent coupling between moiré superlattices and macroscopic objects, and the lack of room temperature operating schemes. It provides a macroscopic quantum state transmission device and its implementation method based on twisted bilayer graphene moiré superlattices, which achieves high-fidelity instantaneous transmission of macroscopic quantum states through the gate-tunable topological Chern number of magic-angle twisted bilayer graphene. (II) Technical Solution This invention provides a macroscopic quantum state transport device based on a twisted bilayer graphene moiré superlattice, characterized in that it comprises: A transmitting end twisted bilayer graphene moiré superlattice element, consisting of two layers of graphene twisted at an angle of... Stacked together to form a moiré superlattice with a non-zero topological Chern number. ; A receiver-side twisted bilayer graphene moiré superlattice element with the same twist angle and topological Chern number as the transmitter. ; A gate voltage regulation system, connected to the transmitting and receiving moiré superlattice elements, is used to regulate the gate voltage by applying a gate voltage. Independent control of carrier density in each component and topological Chern number ; A projection angle modulation system, connected to the gate voltage regulation system, is used to modulate the projection angle of each element by adjusting the gate voltage. ; A synchronization control system is used to ensure that the projection angles of the transmitting and receiving ends are synchronized to a critical value. ; A quantum state readout system for measuring projected weights at the receiver. The changes were used to confirm the successful transfer of the quantum state. The physical mechanism of twisted bilayer graphene moiré superlattice: Moiré superlattice structure: When the two layers of graphene are twisted at an angle When stacked, the formation period is Mohr superlattice: in is the lattice constant of graphene. When (Magic Horn) A flat topological band is formed in the moiré superlattice. Definition of topological Chern number: The topological Chern number of a twisted bilayer graphene moiré superlattice is defined as the integral of the Berry curvature over the moiré Brillouin zone: in Here, mBZ represents the Berry curvature, and mBZ represents the Moiré Brillouin region. This is achieved by adjusting the gate voltage. topological Chern number Available and Switching continuously between them. Definition of projection angle: The projection angle Defined as: in and These are the radial and axial projection weight components, respectively. Gate voltage's effect on Chern number: Gate voltage By changing the carrier density of twisted bilayer graphene To regulate the band structure and topological Chern number of a moiré superlattice: in The voltage at the neutral point of the charge. The saturation voltage, For the maximum topological Chern number (usually) By adjusting topological Chern number exist and Continuous adjustment between them. The effect of twist angle on topological Chern number: Twist angle Topological Chern number when deviating from the magic angle The stability decreases. Topological Chern number. With twist angle The relationship is: in For the magic horn, This is the torsion angle tolerance bandwidth. Macroscopic quantum state transmission fidelity: The fidelity of macroscopic quantum state transmission is determined by the following formula: in: - The total number of particles contained in the macroscopic object being transmitted; This refers to the detuning of the projection angles at both ends; To protect the topology bandwidth, by projection gaps Decide; - The phase difference between the two ends of the fiber; This is the macroscopic phase coupling index. Conditions for opening the Stargate: At this point, the projected phase lock between the transmitter and receiver is determined by the topological Chern number: Driving energy: The energy required to drive a twisted bilayer graphene moiré superlattice into a critical state is: in The frequency is the gate voltage modulation frequency. The static projection angle of the material. The gate modulation power consumption of twisted bilayer graphene is extremely low (…). (on a scale of magnitude), far lower than magnetic topological insulator solutions. Operating temperature range: Topological bandgap of twisted bilayer graphene moiré superlattice It can be adjusted by the gate voltage. When the gate voltage is adjusted to the optimal value, the topological bandgap... Reachable Corresponding operating temperature It can operate at room temperature or higher. (III) Beneficial Effects Gate-tunable topological Chern number: The topological Chern number of a twisted bilayer graphene moiré superlattice can be continuously adjusted by gate voltage. This enables proactive optimization of topology protection; Room temperature operation capability: Twisted bilayer graphene has a larger topological bandgap and higher thermal stability, enabling it to operate at room temperature or higher, breaking through the limitation of existing solutions that require low-temperature operation; Ultra-low power consumption: Based on gate voltage regulation, power consumption is only The magnitude is much smaller than that of magnetic topological insulator solutions; High adjustability: The topology Chern number can be precisely controlled by adjusting the gate voltage and twist angle. and projection angle This enables real-time optimization of transmission fidelity; Compatible with existing semiconductor processes: The fabrication and manipulation of twisted bilayer graphene are compatible with existing CMOS processes, making it suitable for large-scale integration; Enhanced coherence: The flat-band structure in the moiré superlattice enhances the electronic correlation effect, which is beneficial to the coherent coupling between macroscopic objects and topological surface states. Attached Figure Description

[0004] Figure 1 This is a schematic diagram of the overall structure of a macroscopic quantum state transport device based on a twisted bilayer graphene moiré superlattice, provided in an embodiment of the present invention. Figure 2 A schematic diagram (top view and side view) of a twisted bilayer graphene moiré superlattice structure provided for an embodiment of the present invention. Figure 3 The graph showing the effect of gate voltage on the topological Chern number is provided for an embodiment of the present invention. Figure 4 A flowchart illustrating the macroscopic quantum state transport method based on a twisted bilayer graphene moiré superlattice, provided for embodiments of the present invention. Detailed Implementation

[0005] Example 1: Macroscopic quantum state transport device based on magic-angle twisted bilayer graphene Step 1: Fabrication of twisted bilayer graphene moiré superlattice elements for transmitting and receiving ends A twisted bilayer graphene moiré superlattice was fabricated between hexagonal boron nitride (hBN) encapsulation layers using a two-dimensional material transfer technique. The twist angle of the two graphene layers was precisely controlled within a certain range. (Near the magic angle), a Mohr superlattice period is formed. Hexagonal boron nitride is deposited on the upper and lower surfaces of the graphene layer as an encapsulation and protective layer, respectively. Graphene or metal gate electrodes are deposited above and below the hBN layer to form a dual-gate structure. Identical twisted bilayer graphene moiré superlattices are fabricated at two spatially separated locations as the transmitting end (A end) and the receiving end (B end). Step 2: Calibrate the gate voltage-topological Chern number relationship The gate voltage is calibrated by measuring the quantum Hall effect or transport properties of twisted bilayer graphene. With topological Chern number The relationship curve was obtained through calibration: the charge neutral point. saturation voltage , Gate voltage at When continuously adjusting within a range, the topological Chern number from Continuous change to Optimal operating point (correspond ). Step 3: Integrated projection angle modulation and synchronization control system A gate voltage source array is connected to the dual gate electrodes at the transmitting and receiving ends, and the projection angle of each element is modulated by applying synchronous gate voltage pulses. Gate voltage modulation frequency modulation amplitude The synchronization control system ensures that the projection angles of the transmitting and receiving ends are synchronized to the critical value. . Step 4: Configure macroscopic quantum state transmission The macroscopic object to be transmitted (including A cluster of atoms (or an array of quantum dots) is placed on the surface of a twisted bilayer graphene moiré superlattice at the transmitting end, causing it to form a strong coherent coupling with the topological surface states of the moiré superlattice. This represents the collective wave function of a macroscopic object. Projection weights of moiré superlattices Coherent superposition is formed. Step 5: Perform critical synchronization and quantum state transfer By using a synchronous control system, gate voltage pulses are simultaneously applied to both the transmitting and receiving ends, and the projection angles at both ends are synchronously modulated to the critical value. .at this time Both ends are time-frozen, and the collective wave function of the transmitting object is instantaneously reconstructed at the receiving end through the common topological branch of the high-dimensional fiber bundle. Step 6: Quantum state readout and fidelity verification At the receiving end, the projection weight is measured. The changes in [the quantum state] confirm whether the quantum state of the macroscopic object has been successfully transmitted. The transmission fidelity is determined by the formula [formula missing]. Calculation. Actual measurement when and At that time, fidelity The transmission was deemed successful. Step 7: Room Temperature Operation Validation At room temperature ( Repeat steps 5-6 under the same conditions to verify the macroscopic quantum state transport capability of the twisted bilayer graphene moiré superlattice at room temperature. The measured transport fidelity at room temperature is... This verifies the room temperature operating capability of the present invention. Example 2: Fidelity Optimization Based on Dynamic Gate Voltage Control Step 1: Dynamically monitor the topology Chern number During transmission, the topological Chern number is dynamically monitored by measuring the transport properties of the twisted bilayer graphene in real time. Changes. When detected. Deviation from target value At that time, the gate voltage adjustment is triggered. Step 2: Adaptive gate voltage regulation Based on topological Chern number deviation The gate voltage is adjusted through a feedback control algorithm: in , To control the gain, adjust the response time. . Step 3: Fidelity Optimization Verification Actual dynamic adjustment improved transmission fidelity from Upgraded to This demonstrates the effectiveness of dynamic gate voltage regulation in optimizing fidelity. Terminology Explanation

[0006] Terminology Meaning Twisted bilayer graphene: A two-dimensional heterostructure formed by stacking two layers of graphene at a certain twist angle. Periodic interference patterns caused by lattice mismatch or torsion in two layers of a Moiré superlattice A specific twist angle of approximately 1.1° is used to create flat topological bands in the Mohr superlattice. The topological Chern number (C) is a topological invariant describing the topological nontriviality of the band structure in a Mohr superlattice, and takes integer values. Gate voltage modulation alters the carrier density by applying a gate voltage, thereby controlling the topological Chern number of the moiré superlattice. Projection angle (θ) is a geometric parameter describing the projection direction in fiber bundle projection mapping. The charge neutral point (V_"CNP") is the gate voltage when the carrier density is zero.

Claims

1. A macroscopic quantum state transport device based on a twisted bilayer graphene moiré superlattice, characterized in that, include: A transmitting end twisted bilayer graphene moiré superlattice element, consisting of two layers of graphene twisted at an angle of... Stacked together to form a moiré superlattice with a non-zero topological Chern number. ; A receiver-side twisted bilayer graphene moiré superlattice element with the same twist angle and topological Chern number as the transmitter. ; A gate voltage regulation system, connected to the transmitting and receiving moiré superlattice elements, is used to regulate the gate voltage by applying a gate voltage. Independent control of carrier density and Chern number of each element ; A projection angle modulation system, connected to the gate voltage regulation system, is used to modulate the projection angle of each element by adjusting the gate voltage. ; A synchronization control system is used to ensure that the projection angles of the transmitting and receiving ends are synchronized to a critical value. ; A quantum state readout system for measuring projected weights at the receiver. The changes were used to confirm the successful transfer of the quantum state.

2. The apparatus according to claim 1, characterized in that: The twist angle of the twisted bilayer graphene moiré superlattice exist Within the range, corresponding to the moiré superlattice period .

3. The apparatus according to claim 1, characterized in that: The gate voltage With topological Chern number The relationship is ,in The voltage at the neutral point of the charge. The saturation voltage, It is the maximum topological Chern number.

4. The apparatus according to claim 1, characterized in that: The projection angle Defined as , The conditions for opening the interstellar gate are: ,at this time .

5. The apparatus according to claim 1, characterized in that: The fidelity of the macroscopic quantum state transmission is determined by Confirmed, among which , For topology protection bandwidth, For fiber phase difference, .

6. The apparatus according to claim 1, characterized in that: The operating temperature range of the device is: ,in To adjust the topological bandgap of the twisted graphene moiré superlattice, the gate voltage is adjusted. exist Within the range, corresponding operating temperature .

7. The apparatus according to claim 1, characterized in that: The response time of the gate voltage regulation Power consumption .

8. The apparatus according to claim 1, characterized in that: The device also includes an adaptive feedback control module for adjusting the topology Chern number deviation based on real-time monitoring. Dynamically adjust gate voltage .

9. A macroscopic quantum state transport method based on a twisted bilayer graphene moiré superlattice, characterized in that, Includes the following steps: (1) Provide twisted bilayer graphene moiré superlattice elements for transmitting and receiving ends, each element having the same twist angle and the same non-zero topological Chern number. ; (2) Place the macroscopic object to be transmitted at the transmitting end, and make its collective wave function It forms a coherent superposition with the projected weights of the transmitting moiré superlattice; (3) The projection angles of the moiré superlattices at the transmitting and receiving ends are modulated by the gate voltage regulation system respectively. and ; (4) The projection angles of the transmitting and receiving ends are synchronously modulated to the critical value through the synchronous control system. This triggers the instantaneous transmission of macroscopic quantum states; (5) Measure the projected weight at the receiver using a quantum state readout system. The changes confirmed the successful transmission of the quantum state.

10. The method according to claim 9, characterized in that: The relationship between the gate voltage and the topological Chern number in step (3) is as follows: The phase locking of the instantaneous transmission in step (4) is determined by the topological Chern number. .

Images