A method for simultaneous measurement of gravitational and gradient magnetic fields based on an optical lattice ultracold atom system

Abstract

This application discloses a method and related apparatus for simultaneously measuring gravitational and gradient magnetic fields based on an optical lattice ultracold atom system. The method includes constructing an optical lattice ultracold atom system including an artificial compensation potential, wherein the optical lattice ultracold atom system has a double potential well structure; scanning the artificial compensation potential to determine the relationship between the artificial compensation potential and the transition frequencies of the ultracold atoms in the optical lattice ultracold atom system; determining the sign of the total potential energy corresponding to the artificial compensation potential based on the relationship between the artificial compensation potential and the transition frequencies of the ultracold atoms in the optical lattice ultracold atom system, and determining the value of the total potential energy based on the transition frequencies and tunneling intensity corresponding to the artificial compensation potential; and determining the gravitational and gradient magnetic fields in the optical lattice ultracold atom system based on the sign and value of the total potential energy. This application embodiment, by simultaneously measuring the gravitational and gradient magnetic fields, can significantly reduce the system size, weight, and power consumption, promoting the miniaturization and chip-based development of quantum sensors.

Description

Technical Field

[0001] This invention relates to the field of quantum precision measurement technology, and in particular to a method for simultaneously measuring gravitational fields and gradient magnetic fields based on an optical lattice ultracold atom system. Background Technology

[0002] Quantum precision measurement is a crucial field in quantum information technology. Its core lies in utilizing fundamental principles of quantum mechanics, such as quantum superposition, quantum entanglement, and quantum coherence, to achieve highly accurate and precise measurements of physical parameters like magnetic fields, frequencies, electric fields, time, and length. With the continuous maturation and development of cold atom system precision measurement technology, this technology is making breakthroughs towards miniaturization and high integration. Against this backdrop, conducting simultaneous measurements of multiple physical parameters based on cold atom systems has become one of the key technological pathways for improving system integration efficiency and functional density.

[0003] Gravitational fields and gradient magnetic fields reveal secrets of the Earth's interior and the universe from the perspectives of "density" and "magnetism," respectively. Fields such as inertial navigation, geophysical exploration, and space science experiments urgently require high-precision synchronous sensing of gravity and gradient magnetic fields. Traditional measurement methods often treat gravity and magnetic fields separately, resulting in high system redundancy and difficulty in maintaining a consistent spatiotemporal reference in dynamic environments. Therefore, how to simultaneously measure gravity and gradient magnetic fields using quantum precision measurement techniques based on cold atom systems is a crucial technical problem that needs to be solved. Summary of the Invention

[0004] This application provides a method and related apparatus for synchronously measuring gravitational field and gradient magnetic field based on an optical lattice ultracold atom system. By synchronously measuring gravitational field and gradient magnetic field, the system size, weight and power consumption can be significantly reduced, promoting the miniaturization and chip-based development of quantum sensors.

[0005] The first aspect of this application provides a method for simultaneously measuring gravitational fields and gradient magnetic fields based on an optical lattice ultracold atom system, the method comprising: Construct an optical lattice ultracold atom system including an artificial compensation potential, wherein the optical lattice ultracold atom system is a double potential well structure; The artificial compensation potential is scanned to determine the relationship between the artificial compensation potential and the transition frequency of the ultracold atoms in the optical lattice ultracold atom system, wherein the transition frequency is used to represent the frequency at which the ultracold atom transitions from one potential well to another. The sign of the total potential energy corresponding to the artificial compensation potential is determined based on the relationship between the artificial compensation potential and the transition frequency of the ultracold atoms in the optical lattice ultracold atom system, and the value of the total potential energy is determined based on the transition frequency and tunneling intensity corresponding to the artificial compensation potential. The gravitational field and gradient magnetic field in the optical lattice ultracold atom system are determined based on the sign and value of the total potential energy.

[0006] Optionally, determining the sign of the total potential energy corresponding to the artificial compensation potential based on the relationship between the artificial compensation potential and the transition frequencies of the ultracold atoms in the optical lattice ultracold atom system includes: Based on the relationship between the artificial compensation potential and the transition frequency of the ultracold atoms in the optical lattice ultracold atom system, a curve of artificial compensation potential versus transition frequency is plotted. To determine whether any data point is in the rising or falling phase of the curve, the data point is determined based on the artificial compensation potential and the transition frequency corresponding to the artificial compensation potential; If it is in the rising phase, then the sign of the total potential energy corresponding to the data point is determined to be positive; If it is in the descent phase, then the sign of the total potential energy corresponding to the data point is determined to be negative.

[0007] Optionally, the transition frequencies include spin-up transition frequencies and spin-down transition frequencies, the total potential energy includes spin-up total potential energy and spin-down total potential energy, and determining the gravitational field and gradient magnetic field in the optical lattice ultracold atom system based on the sign and value of the total potential energy includes: The total spin-up potential energy is determined based on the sign and value of the total spin-up potential energy, and the total spin-down potential energy is determined based on the sign and value of the total spin-down potential energy. The gravitational field in the optical lattice ultracold atom system is determined by half the sum of the total spin-up potential energy and the total spin-down potential energy, and the gradient magnetic field in the optical lattice ultracold atom system is determined by half the difference between the total spin-up potential energy and the total spin-down potential energy.

[0008] Optionally, scanning the artificial compensation potential to determine the relationship between the artificial compensation potential and the transition frequencies of ultracold atoms in the optical lattice ultracold atom system includes: Obtain the initial value and scan step size of the artificial compensation potential; Starting from the initial value, the value of the artificial compensation potential is increased by the scan step size; For each value of the artificial compensation potential, the quantum state of the ultracold atom in the optical lattice ultracold atom system is measured at preset time intervals to obtain multiple data pairs. Each data pair includes the measurement time and the measurement probability corresponding to the measurement time. The measurement probability is used to characterize the probability that the ultracold atom is in one of the potential wells. Fourier decomposition is performed on multiple data pairs to obtain the transition frequencies of the ultracold atoms at each measurement time; The relationship between the artificial compensation potential and the transition frequency of the ultracold atoms in the optical lattice ultracold atom system is determined based on the value of each artificial compensation potential and the corresponding transition frequency.

[0009] Optionally, the construction includes an optical lattice ultracold atom system with an artificially compensated potential, comprising: Two independent lasers each generate a laser beam, with the wavelength of one laser beam being half the wavelength of the other laser beam. For each laser beam, a beam splitter generates two beams with opposite propagation directions, so that the two beams with opposite propagation directions interfere at the atomic positions to form a standing wave field; The standing wave optical paths corresponding to the two standing wave fields are spatially overlapped, and the relative phase between the two beams of light with opposite propagation directions generated by one of the laser beams through the beam splitter is locked by a phase controller. Thus, a one-dimensional optical lattice is obtained; Ultracold atoms are placed in the one-dimensional optical lattice, and the ultracold atoms are prepared to an initial state. By linearly adjusting the power of the laser output from the third laser using an acousto-optic modulator to change the intensity of the light irradiating the cold atoms, an artificial compensation potential is introduced, resulting in an optical lattice ultracold atom system.

[0010] Optionally, the one-dimensional optical lattice is a double potential well structure, and the potential energy distribution function of the double potential well structure is: , Among them, the momentum is deep , The wave vector of the laser. The angular frequency of the laser. The beam waist radius of the laser. The power of the laser. Microscopic properties related to the scattering medium; The method further includes: Based on the potential well depth of the dual potential well structure Determine the tunneling strength The tunneling strength is: , Among them, recoil energy , where m is the mass of the ultracold atom.

[0011] Optionally, the initial state is: , in, , These represent the spin-up and spin-down quantum states, respectively, within one of the potential wells. , These are the spin-up and spin-down quantum states, respectively, located in another potential well.

[0012] A second aspect of this application provides a device for simultaneously measuring gravitational fields and gradient magnetic fields based on an optical lattice ultracold atom system, the device comprising: A system construction unit is used to construct an optical lattice ultracold atom system including an artificial compensation potential, wherein the optical lattice ultracold atom system is a double potential well structure. The compensation potential scanning unit is used to scan the artificial compensation potential to determine the relationship between the artificial compensation potential and the transition frequency of the ultracold atoms in the optical lattice ultracold atom system. The potential energy determination unit is used to determine the sign of the total potential energy corresponding to the artificial compensation potential based on the relationship between the artificial compensation potential and the transition frequency of the ultracold atoms in the optical lattice ultracold atom system, and to determine the value of the total potential energy based on the transition frequency and tunneling intensity corresponding to the artificial compensation potential. The gravitational field and gradient magnetic field determination unit is used to determine the gravitational field and gradient magnetic field in the optical lattice ultracold atom system based on the sign and value of the total potential energy.

[0013] A third aspect of this application provides an electronic device, including: a processor and a memory; The processor is connected to a memory, wherein the memory is used to store computer programs and the processor is used to invoke the computer programs to execute the methods as described in the first aspect of the embodiments of this application.

[0014] A fourth aspect of this application provides a computer-readable storage medium storing a computer program, the computer program including program instructions, which, when executed by a processor, perform the method as described in the first aspect of this application.

[0015] The technical solution provided in this application has the following technical effects: First, by utilizing the quantum superposition and coherence characteristics of ultracold atoms, the response information of gravitational field and gradient magnetic field can be obtained simultaneously in the same optical lattice system, avoiding the time asynchrony and position deviation introduced by traditional time-sharing or platform-sharing measurements, and significantly improving the spatiotemporal consistency of multi-physics joint measurements.

[0016] Second, by scanning the artificial compensation potential and extracting the atomic transition frequency and tunneling intensity, the sign and value of the total potential energy can be determined, and thus the total potential energy can be determined. The contribution of the gravitational field and the contribution of the gradient magnetic field can be effectively separated from the total potential energy, realizing in-situ decoupling of multiple parameters.

[0017] Third, only one optical lattice device, atomic source and detection optical path are needed to complete the synchronous measurement of two physical parameters. Compared with the combination of discrete gravimeter and magnetometer, the size, weight and power consumption are greatly reduced, which is conducive to the development of chip-based, portable quantum precision measurement equipment, and is suitable for constrained platforms such as aviation, underwater and space.

[0018] Fourth, the synchronously output gravity field and gradient magnetic field data naturally have the same spatial location and time label, which can be directly used in the joint inversion algorithm to eliminate false anomalies caused by data registration errors and improve the reliability of geophysical exploration and navigation matching. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A flowchart illustrating a method for synchronously measuring gravitational and gradient magnetic fields based on an optical lattice ultracold atom system according to an embodiment of this application is shown. Figure 2 A schematic diagram of a dual potential well structure provided in one embodiment of this application is shown; Figure 3 This illustration shows a schematic diagram of the evolution of each quantum over time according to an embodiment of this application; Figure 4 This illustration shows a schematic diagram of the Fourier transform of the time evolution of each quantum state according to an embodiment of this application. Figure 5 It shows a schematic diagram of the transition frequency as a function of artificial compensation potential according to an embodiment of this application; Figure 6 This invention provides a schematic diagram of a device for simultaneously measuring gravitational and gradient magnetic fields based on an optical lattice ultracold atom system according to an embodiment of this application. Figure 7 A schematic diagram of the structure of a computer device provided in one embodiment of this application is shown. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0022] Classical computers use transistors to encode information in binary data, such as bits, where each bit can represent a value of 1 or 0. These 1s and 0s act as switches to drive the functions of a classical computer. If there are n bits of data, there are 2^n possible classical states, and one state is represented at a time.

[0023] Quantum computers use quantum processors that operate on data represented by qubits, also known as quantum bits. A qubit can represent the classical binary states "0" or "1", or a superposition of "0" and "1". Because it can represent a superposition of "0" and "1", a qubit can represent both "0" and "1" states simultaneously. For example, if there are n bits of data, 2^n quantum states can be represented simultaneously. Furthermore, qubits in a superposition can be correlated with each other, a phenomenon known as entanglement. The state of one qubit (whether it's 1, 0, or both) can depend on the state of another qubit, and more information can be encoded within two entangled qubits. Based on the principles of superposition and entanglement, qubits enable quantum computers to perform functions that might be relatively complex and time-consuming for classical computers.

[0024] Please refer to Figure 1 This document illustrates a flowchart of a method for simultaneously measuring gravitational and gradient magnetic fields using an optical lattice ultracold atom system, according to an embodiment of this application. This method can be applied to computer equipment, which refers to electronic devices capable of data computation and processing. The method may include the following steps: Step 101: Construct an optical lattice ultracold atom system including an artificial compensation potential, wherein the optical lattice ultracold atom system is a double potential well structure.

[0025] Among them, the Cold Atomic Lattice Systems are the core experimental platform for ultracold atom physics and quantum simulation. They utilize laser beams to construct periodic "optical lattices" in a vacuum, allowing ultracold atoms (such as bosons) to be visualized. 87 (e.g., Rb) are trapped in artificially designed lattice sites to simulate the behavior of strongly correlated quantum materials in condensed matter physics.

[0026] The double-well structure is a core concept in quantum mechanics and cold atom physics, referring to the existence of two regions in space with the lowest potential energy (i.e., two wells) separated by a potential barrier. In optical lattice ultracold atom systems, double-well structures can typically be realized through optical methods or microstructure potential fields.

[0027] In a specific embodiment provided in this application, taking the optical generation of a double potential well as an example, the structure includes an optical lattice ultracold atom system with artificially compensated potential, comprising: Two independent lasers each generate a laser beam, with the wavelength of one laser beam being half the wavelength of the other laser beam. For each laser beam, a beam splitter generates two beams with opposite propagation directions, so that the two beams with opposite propagation directions interfere at the atomic positions to form a standing wave field; The standing wave optical paths corresponding to the two standing wave fields are spatially overlapped, and the relative phase between the two beams of light with opposite propagation directions generated by one of the laser beams through the beam splitter is locked by a phase controller. Thus, a one-dimensional optical lattice is obtained; Ultracold atoms are placed in the one-dimensional optical lattice, and the ultracold atoms are prepared to an initial state. By linearly adjusting the power of the laser output from the third laser using an acousto-optic modulator to change the intensity of the light irradiating the cold atoms, an artificial compensation potential is introduced, resulting in an optical lattice ultracold atom system.

[0028] Please refer to Figure 2 This diagram illustrates a double-potential-well structure provided in one embodiment of this application. The one-dimensional optical lattice is a double-potential-well structure, and the potential energy distribution function of the double-potential-well structure is: , Among them, the momentum is deep , The wave vector of the laser. , The wavelength of the laser. The angular frequency of the laser. , The frequency of the laser, The beam waist radius of the laser. The power of the laser. Microscopic properties related to the scattering medium; The natural linewidth of the excited state of the atom. This is the laser detuning (the difference between the laser detuning and the atomic transition frequency).

[0029] like Figure 2 As shown, the two laser beams have equal power, and one has a wavelength of [missing information]. The other is For example, one could adopt... and Two laser beams. The first laser beam forms a standing wave field. The second laser beam forms a standing wave field. By spatially overlapping the standing wave optical paths corresponding to the two standing wave fields, that is, through precise optical adjustment, the standing wave fields are made... The corresponding laser propagation path (i.e., standing wave optical path) and standing wave field The corresponding laser propagation paths (i.e., standing wave paths) completely overlap, and the areas where they interact (i.e., the areas intersecting with the atomic cloud) are also exactly the same. This is not merely about making the two beams cross, but about making them travel along the same axis and cover the same space.

[0030] The initial state is: , in, , These represent the spin-up and spin-down quantum states, respectively, within one of the potential wells. , These are the spin-up and spin-down quantum states, respectively, located in another potential well.

[0031] For example, one of the potential wells can be Figure 2 The left potential well in the middle, the other potential well can be Figure 2 The right potential trap in the middle can, of course, be reversed, but it is not limited here.

[0032] After the initial state is prepared, the ultracold atoms will evolve in the system over time, such as... Figure 3 As shown, this diagram illustrates the evolution of each quantum over time according to an embodiment of this application. Taking the initial state above as an example, the red solid line represents the probability of a spin-up atom in the left well, the blue solid line represents the probability of a spin-up atom in the right well, the green dashed line represents the probability of a spin-down atom in the left well, and the red dashed line represents the probability of a spin-down atom in the right well.

[0033] It can be seen that the initial state described above is the direct product of the maximally coherent states, which are independent of spatial and spin degrees of freedom, rather than an entangled state. The gravitational field only acts on the spatial degree of freedom, affecting the relative phase of the left and right wells, but not the spin. The gradient magnetic field acts on both the spatial and spin degrees of freedom, but more importantly, the magnetic field gradient causes different spin states to experience different spatial potential energy differences. If only a spatial superposition state is prepared... Therefore, only gravity can be measured, and magnetic field gradients cannot be distinguished. If only spin superposition states are prepared... This approach can only measure the magnitude of the magnetic field, not its gradient. However, this method combines both, allowing the evolved phase information to carry the contributions of both the gravitational field and the magnetic field gradient. Subsequent spin-resolved and space-resolved detections can then decouple the two.

[0034] In addition, this initial state has an equal probability distribution for all four basis vectors, and can be prepared experimentally from a simple initial state using carefully designed microwave or Raman pulse sequences. During the evolution process, external common-mode noise... and The effects are approximately the same, and can ultimately be significantly suppressed through differential measurement (comparing the phase difference between different spin channels).

[0035] Step 102: Scan the artificial compensation potential to determine the relationship between the artificial compensation potential and the transition frequency of the ultracold atoms in the optical lattice ultracold atom system, wherein the transition frequency is used to represent the frequency at which the ultracold atom transitions from one potential well to another.

[0036] Or as Figure 2 As shown, the transition frequency can represent the frequency at which an ultracold atom transitions from the left well to the right well. Since the two are symmetrical, it can also represent the frequency at which an ultracold atom transitions from the right well to the left well.

[0037] Specifically, scanning the artificial compensation potential to determine the relationship between the artificial compensation potential and the transition frequencies of ultracold atoms in the optical lattice ultracold atom system includes: Obtain the initial value and scan step size of the artificial compensation potential; Starting from the initial value, the value of the artificial compensation potential is increased by the scan step size; For each value of the artificial compensation potential, the quantum state of the ultracold atom in the optical lattice ultracold atom system is measured at preset time intervals to obtain multiple data pairs. Each data pair includes the measurement time and the measurement probability corresponding to the measurement time. The measurement probability is used to characterize the probability that the ultracold atom is in one of the potential wells. Fourier decomposition is performed on multiple data pairs to obtain the transition frequencies of the ultracold atoms at each measurement time; The relationship between the artificial compensation potential and the transition frequency of the ultracold atoms in the optical lattice ultracold atom system is determined based on the value of each artificial compensation potential and the corresponding transition frequency.

[0038] The initial value and scanning step size of the artificial compensation potential are preset and can be determined approximately based on experience or theoretical data. For example, the artificial compensation potential... For example, it can take the value of , , ··· , where n is the preset number of scans. This is the initial value of the artificial compensation potential. The difference between any two adjacent values ​​is equal, which equals the scan step size. For example, .

[0039] For example, the data pair corresponding to the value of each artificial compensation potential can be represented as follows: With probe states of different spins as initial states, the wavefunction of the system evolves over time in the basis vectors. or The projection probabilities are as follows: Among them, the transition frequency of ultracold atoms , , This represents the total potential energy.

[0040] Fourier decomposition of the above relationship yields the transition frequencies. The relationship with amplitude, where amplitude is the squared modulus of the projected probability. Therefore, for data pairs... By performing Fourier decomposition, the transition frequencies can be obtained. The relationship with amplitude. For example... Figure 4 The diagram illustrates a schematic representation of the Fourier transform of the time evolution of each quantum state according to an embodiment of this application. The red solid line represents the spectrum of a spin-up atom in the left well, the blue solid line represents the spectrum of a spin-up atom in the right well, the green dashed line represents the spectrum of a spin-down atom in the left well, and the pink dashed line represents the spectrum of a spin-down atom in the right well.

[0041] The transition frequencies corresponding to each quantum state can be read from the graph. .according to It can be deduced that It can be seen that for each It can be determined The numerical value of the potential can be determined, but its sign cannot be determined. Therefore, an artificial compensation potential is introduced in this application.

[0042] Scanning the artificial compensation potential, then for each artificial compensation potential... A transition frequency can be obtained from all of them. For example, The corresponding transition frequency is , The corresponding transition frequency is , The corresponding transition frequency is ··· The corresponding transition frequency is Based on the value of each artificial compensation potential and the corresponding transition frequency, the relationship between the artificial compensation potential and the transition frequency can be determined. This relationship can be represented by a function or a graph, which is not limited here. Figure 5 The diagram illustrates a schematic representation of the change in transition frequency with artificial compensation potential according to an embodiment of this application. The solid blue line represents a schematic representation of the change in transition frequency of spin-up atoms with artificial compensation potential, and the dashed red line represents a schematic representation of the change in transition frequency of spin-down atoms with artificial compensation potential.

[0043] Furthermore, the method also includes: Based on the potential well depth of the dual potential well structure Determine the tunneling strength The tunneling strength is: , Among them, recoil energy , where m is the mass of the ultracold atom.

[0044] Step 103: Determine the sign of the total potential energy corresponding to the artificial compensation potential based on the relationship between the artificial compensation potential and the transition frequency of the ultracold atoms in the optical lattice ultracold atom system, and determine the value of the total potential energy based on the transition frequency and tunneling intensity corresponding to the artificial compensation potential.

[0045] Specifically, determining the sign of the total potential energy corresponding to the artificial compensation potential based on the relationship between the artificial compensation potential and the transition frequencies of the ultracold atoms in the optical lattice ultracold atom system includes: Based on the relationship between the artificial compensation potential and the transition frequency of the ultracold atoms in the optical lattice ultracold atom system, a curve of artificial compensation potential versus transition frequency is plotted. To determine whether any data point is in the rising or falling phase of the curve, the data point is determined based on the artificial compensation potential and the transition frequency corresponding to the artificial compensation potential; If it is in the rising phase, then the sign of the total potential energy corresponding to the data point is determined to be positive; If it is in the descent phase, then the sign of the total potential energy corresponding to the data point is determined to be negative.

[0046] Or with Figure 5 For example, a curve can be plotted based on the relationship between the artificial compensation potential and the transition frequency. From... Figure 5 As can be seen, for both spin-up and spin-down, the curve is a parabola. To the left of the vertex of the parabola, the corresponding transition frequency decreases as the artificial compensation potential increases, meaning it is in the decreasing phase; therefore, the total potential energy obtained from the transition frequency in this part is negative. To the right of the vertex of the parabola, the corresponding transition frequency increases as the artificial compensation potential increases, meaning it is in the increasing phase; therefore, the total potential energy obtained from the transition frequency in this part is positive.

[0047] Step 104: Determine the gravitational field and gradient magnetic field in the optical lattice ultracold atom system based on the sign and value of the total potential energy.

[0048] Specifically, the transition frequencies include spin-up transition frequencies and spin-down transition frequencies, the total potential energy includes spin-up total potential energy and spin-down total potential energy, and determining the gravitational field and gradient magnetic field in the optical lattice ultracold atom system based on the sign and value of the total potential energy includes: The total spin-up potential energy is determined based on the sign and value of the total spin-up potential energy, and the total spin-down potential energy is determined based on the sign and value of the total spin-down potential energy. The gravitational field in the optical lattice ultracold atom system is determined by half the sum of the total spin-up potential energy and the total spin-down potential energy, and the gradient magnetic field in the optical lattice ultracold atom system is determined by half the difference between the total spin-up potential energy and the total spin-down potential energy.

[0049] For example, , , in, , These are the total potential energy of spin-up and the total potential energy of spin-down, respectively. , Let gravitational field and gradient magnetic field be the two forces, respectively. Applying the difference between the two equations, we get: , .

[0050] It can be seen that the technical solution provided in this application has the following technical effects: First, by utilizing the quantum superposition and coherence characteristics of ultracold atoms, the response information of gravitational field and gradient magnetic field can be obtained simultaneously in the same optical lattice system, avoiding the time asynchrony and position deviation introduced by traditional time-sharing or platform-sharing measurements, and significantly improving the spatiotemporal consistency of multi-physics joint measurements.

[0051] Second, by scanning the artificial compensation potential and extracting the atomic transition frequency and tunneling intensity, the sign and value of the total potential energy can be determined, and thus the total potential energy can be determined. The contribution of the gravitational field and the contribution of the gradient magnetic field can be effectively separated from the total potential energy, realizing in-situ decoupling of multiple parameters.

[0052] Third, only one optical lattice device, atomic source and detection optical path are needed to complete the synchronous measurement of two physical parameters. Compared with the combination of discrete gravimeter and magnetometer, the size, weight and power consumption are greatly reduced, which is conducive to the development of chip-based, portable quantum precision measurement equipment, and is suitable for constrained platforms such as aviation, underwater and space.

[0053] Fourth, the synchronously output gravity field and gradient magnetic field data naturally have the same spatial location and time label, which can be directly used in the joint inversion algorithm to eliminate false anomalies caused by data registration errors and improve the reliability of geophysical exploration and navigation matching.

[0054] Figure 6 A schematic diagram of a device for simultaneously measuring gravitational and gradient magnetic fields based on an optical lattice ultracold atom system, according to an embodiment of this application, is shown. The device includes: System construction unit 601 is used to construct an optical lattice ultracold atom system including an artificial compensation potential, wherein the optical lattice ultracold atom system is a double potential well structure; The compensation potential scanning unit 602 is used to scan the artificial compensation potential to determine the relationship between the artificial compensation potential and the transition frequency of the ultracold atoms in the optical lattice ultracold atom system. The transition frequency is used to represent the frequency at which the ultracold atom transitions from one potential well to another. The potential energy determination unit 603 is used to determine the sign of the total potential energy corresponding to the artificial compensation potential based on the relationship between the artificial compensation potential and the transition frequency of the ultracold atoms in the optical lattice ultracold atom system, and to determine the value of the total potential energy based on the transition frequency and tunneling intensity corresponding to the artificial compensation potential. The gravitational field and gradient magnetic field determination unit 604 is used to determine the gravitational field and gradient magnetic field in the optical lattice ultracold atom system based on the sign and value of the total potential energy.

[0055] Figure 7 The diagram shows a schematic of the structure of a computer device provided in one embodiment of this application, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the function of the computer system based on the method for synchronously measuring gravitational field and gradient magnetic field of optical lattice ultracold atom system in any of the above embodiments.

[0056] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a computer, causes the computer to perform the functions of the computer system based on the method for synchronously measuring gravitational field and gradient magnetic field using an optical lattice ultracold atom system in any of the above embodiments.

[0057] This application also provides a computer program product containing instructions that, when executed by a computer, cause the computer to perform the functions of the computer system based on the method for synchronously measuring gravitational fields and gradient magnetic fields using an optical lattice ultracold atom system in any of the above embodiments.

[0058] It is understood that the specific examples in this application are only intended to help those skilled in the art better understand the implementation methods of this application, and are not intended to limit the scope of the invention.

[0059] It is understood that in the various embodiments of this application, the numerical value of the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not limit the implementation process of the embodiments of this application in any way.

[0060] It is understood that the various implementation methods described in this application can be implemented individually or in combination, and the implementation methods in this application are not limited in this respect.

[0061] Unless otherwise stated, all technical and scientific terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items. The singular forms "a," "the," and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0062] It is understood that the processor in the embodiments of this application can be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiments can be completed by the integrated logic circuits in the processor's hardware or by instructions in software form. The processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory; the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method.

[0063] It is understood that the memory in the embodiments of this application may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. Specifically, non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory may be random access memory (RAM). It should be noted that the memory in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0064] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0065] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the aforementioned method implementations, and will not be repeated here.

[0066] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0067] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0068] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0069] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0070] The above are merely specific embodiments of this application, but the scope of protection of this invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this invention should be determined by the scope of the claims.

Claims

1. A method for simultaneously measuring gravitational field and gradient magnetic field based on an optical lattice ultracold atom system, characterized in that, The method includes: Construct an optical lattice ultracold atom system including an artificial compensation potential, wherein the optical lattice ultracold atom system is a double potential well structure; The artificial compensation potential is scanned to determine the relationship between the artificial compensation potential and the transition frequency of the ultracold atoms in the optical lattice ultracold atom system, wherein the transition frequency is used to represent the frequency at which the ultracold atom transitions from one potential well to another. The sign of the total potential energy corresponding to the artificial compensation potential is determined based on the relationship between the artificial compensation potential and the transition frequency of the ultracold atoms in the optical lattice ultracold atom system, and the value of the total potential energy is determined based on the transition frequency and tunneling intensity corresponding to the artificial compensation potential. The gravitational field and gradient magnetic field in the optical lattice ultracold atom system are determined based on the sign and value of the total potential energy.

2. The method according to claim 1, characterized in that, The step of determining the sign of the total potential energy corresponding to the artificial compensation potential based on the relationship between the artificial compensation potential and the transition frequencies of the ultracold atoms in the optical lattice ultracold atom system includes: Based on the relationship between the artificial compensation potential and the transition frequency of the ultracold atoms in the optical lattice ultracold atom system, a curve of artificial compensation potential versus transition frequency is plotted. To determine whether any data point is in the rising or falling phase of the curve, the data point is determined based on the artificial compensation potential and the transition frequency corresponding to the artificial compensation potential; If it is in the rising phase, then the sign of the total potential energy corresponding to the data point is determined to be positive; If it is in the descent phase, then the sign of the total potential energy corresponding to the data point is determined to be negative.

3. The method according to claim 1 or 2, characterized in that, The transition frequencies include spin-up transition frequencies and spin-down transition frequencies, and the total potential energy includes spin-up total potential energy and spin-down total potential energy. Determining the gravitational field and gradient magnetic field in the optical lattice ultracold atom system based on the sign and value of the total potential energy includes: The total spin-up potential energy is determined based on the sign and value of the total spin-up potential energy, and the total spin-down potential energy is determined based on the sign and value of the total spin-down potential energy. The gravitational field in the optical lattice ultracold atom system is determined by half the sum of the total spin-up potential energy and the total spin-down potential energy, and the gradient magnetic field in the optical lattice ultracold atom system is determined by half the difference between the total spin-up potential energy and the total spin-down potential energy.

4. The method according to claim 1, characterized in that, The step of scanning the artificial compensation potential to determine the relationship between the artificial compensation potential and the transition frequencies of ultracold atoms in the optical lattice ultracold atom system includes: Obtain the initial value and scan step size of the artificial compensation potential; Starting from the initial value, the value of the artificial compensation potential is increased by the scan step size; For each value of the artificial compensation potential, the quantum state of the ultracold atom in the optical lattice ultracold atom system is measured at preset time intervals to obtain multiple data pairs. Each data pair includes the measurement time and the measurement probability corresponding to the measurement time. The measurement probability is used to characterize the probability that the ultracold atom is in one of the potential wells. Fourier decomposition is performed on multiple data pairs to obtain the transition frequencies of the ultracold atoms at each measurement time; The relationship between the artificial compensation potential and the transition frequency of the ultracold atoms in the optical lattice ultracold atom system is determined based on the value of each artificial compensation potential and the corresponding transition frequency.

5. The method according to claim 1, characterized in that, The structure comprises an optical lattice ultracold atom system with an artificially compensated potential, including: Two independent lasers each generate a laser beam, with the wavelength of one laser beam being half the wavelength of the other laser beam. For each laser beam, a beam splitter generates two beams with opposite propagation directions, so that the two beams with opposite propagation directions interfere at the atomic positions to form a standing wave field; The standing wave optical paths corresponding to the two standing wave fields are spatially overlapped, and the relative phase between the two beams of light with opposite propagation directions generated by one of the laser beams through the beam splitter is locked by a phase controller. Thus, a one-dimensional optical lattice is obtained; Ultracold atoms are placed in the one-dimensional optical lattice, and the ultracold atoms are prepared to an initial state. By linearly adjusting the power of the laser output from the third laser using an acousto-optic modulator to change the intensity of the light irradiating the cold atoms, an artificial compensation potential is introduced, resulting in an optical lattice ultracold atom system.

6. The method according to claim 5, characterized in that, The one-dimensional optical lattice is a double potential well structure, and the potential energy distribution function of the double potential well structure is: ， Among them, the momentum is deep , The wave vector of the laser. The angular frequency of the laser. The beam waist radius of the laser. The power of the laser. Microscopic properties related to the scattering medium; The method further includes: Based on the potential well depth of the dual potential well structure Determine the tunneling strength The tunneling strength is: ， Among them, recoil energy , where m is the mass of the ultracold atom.

7. The method according to claim 5, characterized in that, The initial state is: ， in, , These represent the spin-up and spin-down quantum states, respectively, within one of the potential wells. , These are the spin-up and spin-down quantum states, respectively, located in another potential well.

8. A device for simultaneously measuring gravitational field and gradient magnetic field based on an optical lattice ultracold atom system, characterized in that, The device includes: A system construction unit is used to construct an optical lattice ultracold atom system including an artificial compensation potential, wherein the optical lattice ultracold atom system is a double potential well structure. The compensation potential scanning unit is used to scan the artificial compensation potential to determine the relationship between the artificial compensation potential and the transition frequency of the ultracold atoms in the optical lattice ultracold atom system. The transition frequency is used to represent the frequency at which the ultracold atom transitions from one potential well to another. The potential energy determination unit is used to determine the sign of the total potential energy corresponding to the artificial compensation potential based on the relationship between the artificial compensation potential and the transition frequency of the ultracold atoms in the optical lattice ultracold atom system, and to determine the value of the total potential energy based on the transition frequency and tunneling intensity corresponding to the artificial compensation potential. The gravitational field and gradient magnetic field determination unit is used to determine the gravitational field and gradient magnetic field in the optical lattice ultracold atom system based on the sign and value of the total potential energy.

9. An electronic device, characterized in that, include: Processor and memory; The processor is connected to a memory, wherein the memory is used to store a computer program, and the processor is used to invoke the computer program to perform the method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, the computer program including program instructions that, when executed by a processor, perform the method as described in any one of claims 1-7.

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