Method for simultaneously realizing quantum compression of double mechanical oscillators based on light power system
By combining Duffing mechanical nonlinearity and quadratic optical power coupling, quantum compression of dual mechanical oscillators is achieved, solving the 3dB limit and single oscillator limitation problems, and improving the control capability and stability of the multi-vibrator system.
Patent Information
- Application Number
- CN202510860034.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-25
- Publication Date
- 2025-08-08
AI Technical Summary
The prior art is difficult to break through the 3dB limit, limiting the quantum noise compression of mechanical oscillators, and the single oscillator solution is difficult to meet the coordinated control needs of multi-body quantum systems. Especially in low-altitude quantum communication, the drone relay node needs to synchronize the compression state of multiple mechanical oscillators.
Using a light force system, combining Duffing mechanical nonlinear and quadratic optical force coupling, two Fabripes cavity, coil spring, partially reflected elastic film and capacitor are used to amplify the two mechanical oscillators by parametrically and cool the ground state respectively to achieve quantum compression of the dual mechanical oscillators.
It breaks the 3dB limit of dual mechanical oscillators, realizes effective quantum compression of multi-mechanical oscillators, improves the practicality of quantum information processing and the collective control capabilities of multi-body quantum systems, and has robustness and stable existence in high-temperature environments.
Smart Images
Figure CN120447193A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of cavity optomechanics and relates to a method for simultaneously realizing quantum compression of dual mechanical oscillators based on an optomechanical system. Background Art
[0002] Mechanical compression technology manipulates the quantum state of mechanical oscillators to selectively suppress the quantum noise of their position or momentum components, lowering it below the standard quantum limit (the limit dominated by thermal noise or quantum fluctuations), thereby improving the measurement sensitivity of physical quantities such as force, displacement, and mass. Therefore, it is expected to play an important role in low-altitude resource exploration or underground facility detection, as well as in the construction of low-altitude quantum communication networks (such as drone relay stations). Current mainstream solutions rely on parametric amplification (such as optomechanical coupling systems) or measurement-based feedback control, but there are two major technical barriers:
[0003] 1) 3dB Limit: In quantum precision measurement and nonlinear systems, the "3dB limit" specifically refers to the theoretical boundary that cannot be broken when compressing quantum noise through parametric amplification. During degenerate parametric amplification, the balance between the effective damping rate of the mechanical mode and the gain leads to a sharp decline in system stability, limiting the compression factor to 50% (i.e., the noise power must be no less than 1 / 2 of the SQL). This severely restricts improvements in ultra-precision measurement performance (e.g., improving the signal-to-noise ratio of microgravity signals in underground mineral exploration).
[0004] 2) Limitations of Single Oscillators: Existing research focuses on single-oscillator compression (e.g., cantilever beams or microcavity optomechanical systems), which is difficult to meet the requirements of coordinated control of multi-body quantum systems. For example, in low-altitude quantum communication networks, drone relay nodes need to simultaneously process the compressed states of multiple mechanical oscillators to increase channel capacity. However, traditional single-oscillator solutions lead to inefficient quantum resource allocation.
[0005] In recent years, interdisciplinary research has revealed the critical role of multi-oscillator compression in distributed quantum sensing networks. By establishing quantum correlations between oscillators, it is possible to break through the single-node measurement limit and achieve sub-SQL cluster sensitivity. However, existing technologies lack a mechanism for collaboratively suppressing multi-oscillator coupling noise, and cross-modal phase locking accuracy is insufficient. Therefore, the development of new compression architectures is urgently needed to address the multi-degree-of-freedom control challenges. Summary of the Invention
[0006] In view of this, the purpose of the present invention is to provide a method for simultaneously realizing quantum compression of two mechanical oscillators based on an optomechanical system, introducing Duffing mechanical nonlinearity and quadratic optomechanical coupling into the optomechanical system at the same time, utilizing Duffing mechanical nonlinearity and quadratic optomechanical coupling to perform parametric amplification of the two mechanical oscillators respectively, combining optomechanical action and mechanical coupling to perform ground state cooling of the two mechanical oscillators, and designing a method for simultaneously generating strong compression of two mechanical oscillators. This system has the advantages of simultaneously breaking the 3dB limit of the two mechanical oscillators and effectively realizing the regulation of quantum compression of multiple mechanical oscillators.
[0007] In order to achieve the above object, the present invention provides the following technical solutions:
[0008] Scheme 1: A photomechanical system comprising two Fabry-Perot cavities, a coil spring 3, a partially reflective elastic film 5, a capacitor, and two strong pump fields;
[0009] The left-side cavity mirror Ⅰ1 of the first Fabry-Perot cavity is a partially transmissive fixed mirror, and the right-side cavity mirror Ⅰ2 is a movable mirror capable of total reflection, which is connected to the coil spring 3; in the second Fabry-Perot cavity, the elastic film 5 is placed in the center of the cavity; the elastic film 5 and the right-side cavity mirror Ⅰ2 in the first Fabry-Perot cavity are coupled through capacitance as a medium; two strong pump fields are injected into the two Fabry-Perot cavities respectively to drive the movement of photons.
[0010] After the first strong pump field drives the first Fabry-Perot cavity, the photons in the cavity will move back and forth. The photons with momentum will hit the movable mirror, causing mechanical displacement. The movable mirror can vibrate as the first mechanical oscillator q1, changing the cavity length and causing the resonant frequency of the cavity to change. At the same time, the mechanical oscillator q1 is a mechanical oscillator with Duffing nonlinearity.
[0011] The elastic film 5 will divide the second Fabry-Perot cavity into two left and right sub-cavities, serving as the second mechanical oscillator q2; the first sub-cavity is composed of the fixed left cavity mirror Ⅱ4 and the elastic film 5, and the second sub-cavity is composed of the fixed right cavity mirror Ⅱ6 and the elastic film 5; after the second strong pump field is incident on the second Fabry-Perot cavity, it can drive the vibration of the elastic film 5, change the cavity length of the two sub-cavities, cause the optical-mechanical coupling of the two sub-cavities to change, and finally generate the quadratic optical-mechanical coupling between the cavity field and the film.
[0012] The second mechanical oscillator q2 exchanges energy with the first mechanical oscillator q1 having Duffing nonlinearity through the capacitor C as a medium, thereby achieving mechanical coupling.
[0013] Scheme 2: A method for simultaneously achieving quantum compression of two mechanical oscillators based on an optomechanical system (Scheme 1), with the following specific steps:
[0014] Two continuous-wave single-frequency solid-state lasers output two strong pump fields, which are injected into the left and right Fabry-Perot cavities respectively;
[0015] Frequency is ω L1 The first strong pump field is incident on the first Fabry-Perot cavity, stimulating the mechanical displacement of the right cavity mirror Ⅰ2, affecting the change of the cavity length, and realizing the single-photon linear optical force coupling between the cavity field in the first cavity and the first mechanical oscillator q1.
[0016] Frequency is ω L2 After the second strong pump field is incident on the second Fabry-Perot cavity, it excites the mechanical vibration of the elastic film 5. Since the elastic film is placed exactly in the center of the cavity, the vibration of the elastic film will cause the cavity lengths in the two sub-cavities to change in opposite ways, ultimately generating a quadratic optical-mechanical coupling between the second cavity field and the second mechanical oscillator q2.
[0017] Using the linearized approximation method, under the conditions of weak single-photon linear optomechanical coupling and even weaker single-photon quadratic optomechanical coupling, the classical steady-state amplitude of the cavity field is not affected by the optomechanical coupling and can be independently controlled by the driving frequency and phase of the second strong pump field.
[0018] The driving phase of the two pump fields is adjusted so that the steady-state amplitudes of the two cavity fields are both real numbers, and the optomechanical coupling under the action of a strong pump field can be further amplified. Finally, the existence of Duffing nonlinearity and quadratic optomechanical coupling can produce parametric amplification of the right cavity mirror Ⅰ2 and the second mechanical oscillator q2, respectively.
[0019] The mechanical modes of the two mechanical oscillators are compressed and transformed respectively. Under the compression transformation phenomenon, the resonance frequencies of the two compression mechanical modes are made equal, producing a "beam splitter" type mechanical effect.
[0020] By controlling the frequency detuning between the first strong pump field and the resonance frequency of the first Fabry-Perot cavity, the red detuned sideband optical mode in the first Fabry-Perot cavity and the mechanical mode of the first mechanical oscillator resonate simultaneously.
[0021] The photomechanical coupling generated by the driving of the first strong pump field can provide a cooling path for the first mechanical oscillator, and the mechanical coupling between the two mechanical oscillators can extract thermal excitation from the second mechanical oscillator, thereby achieving the purpose of cooling the second mechanical oscillator.
[0022] Cooling is a prerequisite for mechanical compression, and system stability is ensured by the cooling mechanism. Parametric amplification induced by Duffing nonlinearity and quadratic optomechanical coupling is the source of mechanical compression between the two mechanical oscillators. Ultimately, the combined effects of optomechanical cooling and parametric amplification enable simultaneous quantum compression of the two mechanical oscillators without destabilizing the system.
[0023] The beneficial effects of the present invention are:
[0024] (1) The present invention simultaneously introduces Duffing mechanical nonlinearity and quadratic optomechanical coupling into the optomechanical system, utilizes Duffing mechanical nonlinearity and quadratic optomechanical coupling to perform parametric amplification on two mechanical oscillators respectively, combines optomechanical action and mechanical coupling to perform ground state cooling on the two mechanical oscillators, and designs a method for simultaneously generating strong compression of two mechanical oscillators. This system has the advantages of simultaneously breaking the 3dB limit of the two mechanical oscillators and effectively realizing the regulation of quantum compression of multiple mechanical oscillators.
[0025] (2) The present invention can not only generate strong quantum compression of dual mechanical oscillators that can effectively exist in a low-temperature environment, breaking the 3dB limit, but also the mechanical compression of the dual mechanical oscillators generated has a certain robustness to the thermal noise of the environment and can also exist stably at higher ambient temperatures. By utilizing this robustness, the practical potential of the quantum compression state of multiple mechanical oscillators in the collective manipulation of multi-body quantum systems can be significantly enhanced, contributing to improving the practicality of mechanical compression of multiple mechanical oscillators in quantum information processing.
[0026] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings, in which:
[0028] Figure 1 A diagram showing the physical model of the optical force system used to achieve dual-mechanical oscillator quantum squeezing.
[0029] Figure 2 This is a graph showing how the displacement-variance fluctuations of the dual mechanical modes in the optomechanical system change with the frequency detuning of the first strong pump field and the first optical cavity under different thermal phonon numbers. DETAILED DESCRIPTION
[0030] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.
[0031] Among them, the accompanying drawings are only for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting the present invention. In order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the dimensions of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the accompanying drawings.
[0032] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "back", etc. indicating directions or positional relationships, they are based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.
[0033] Example 1:
[0034] Figure 1 The figure shows a physical model of an optomechanical system for simultaneously achieving quantum squeezing of two mechanical oscillators, as provided in this embodiment. The optomechanical system comprises two Fabry-Perot cavities, a coil spring, a partially reflective elastic film 5, a capacitor, and two strong pump fields. The left-hand mirror I1 of the first Fabry-Perot cavity is a partially transmissive fixed mirror, while the right-hand mirror I2 is a movable mirror capable of total reflection, connected to the coil spring 3. In the second Fabry-Perot cavity, the elastic film 5 is placed in the exact center of the cavity. The elastic film 5 is coupled to the movable mirror of the first Fabry-Perot cavity via a capacitor.
[0035] After the first strong pump field drives the first Fabry-Perot cavity, photons within the cavity move back and forth. The photons with momentum collide with the movable cavity mirror, generating mechanical displacement. This movable cavity mirror acts as the first mechanical oscillator q1, vibrating and changing the cavity length, resulting in a change in the cavity's resonant frequency. This mechanical oscillator also exhibits Duffing nonlinearity.
[0036] The elastic membrane divides the second Fabry-Perot cavity into two left and right sub-cavities, serving as the second mechanical oscillator q2. The first sub-cavity is composed of the fixed left-side cavity mirror II4 and the elastic membrane 5, while the second sub-cavity is composed of the fixed right-side cavity mirror II6 and the elastic membrane 5. A second strong pump field incident on the second Fabry-Perot cavity drives the membrane to vibrate, changing the cavity lengths of the two sub-cavities and altering the optomechanical coupling between them, ultimately generating quadratic optomechanical coupling between the cavity field and the membrane.
[0037] The thin film mechanical oscillator exchanges energy with the first mechanical oscillator having Duffing nonlinearity through the capacitor C as a medium, thereby achieving mechanical coupling.
[0038] Example 2:
[0039] This embodiment provides a method for simultaneously generating quantum compression of two mechanical oscillators, comprising the following steps:
[0040] Two continuous-wave single-frequency solid-state lasers output two strong pump fields, which are injected into the left and right Fabry-Perot cavities respectively.
[0041] Frequency is ω L1 The first strong pump field is incident on the first Fabry-Perot cavity, stimulating the mechanical displacement of the movable cavity mirror on the right, affecting the change of the cavity length, and realizing the single-photon linear optical force coupling between the cavity field and the mechanical oscillator in the first cavity.
[0042] Frequency is ω L2 When the second strong pump field is incident on the second Fabry-Perot cavity, it excites the mechanical vibration of the elastic film. Since the elastic film is placed exactly in the center of the cavity, the vibration of the elastic film will cause the cavity lengths in the two sub-cavities to change in opposite directions, ultimately generating quadratic optomechanical coupling between the second cavity field and the film oscillator.
[0043] Using the linearized approximation method, under the conditions of weak single-photon linear optomechanical coupling and even weaker single-photon quadratic optomechanical coupling, the classical steady-state amplitude of the cavity mode is not affected by the optomechanical coupling and can be independently controlled by the driving frequency and phase of the second strong pump field.
[0044] The driving phase of the two pump fields is adjusted so that the steady-state amplitudes of the two cavity fields are both real numbers. Considering that the optomechanical coupling under the action of a strong pump field can be further amplified, the existence of Duffing nonlinearity and quadratic optomechanical coupling can produce parametric amplification of the first movable cavity mirror and the thin film oscillator, respectively.
[0045] The mechanical modes of the two mechanical oscillators are compressed and transformed respectively. Under the compression transformation phenomenon, the resonance frequencies of the two compressed mechanical modes are made equal, resulting in a "beam splitter" type mechanical effect.
[0046] By controlling the frequency detuning between the first strong pump field and the resonance frequency of the first Fabry-Perot cavity, the red detuned sideband optical mode in the first Fabry-Perot cavity and the mechanical mode of the first mechanical oscillator resonate simultaneously.
[0047] The photomechanical coupling generated by the driving of the first strong pump field can provide a cooling path for the first mechanical oscillator, and the mechanical coupling between the two mechanical oscillators can extract thermal excitation from the second mechanical oscillator, thereby achieving the purpose of cooling the second mechanical oscillator.
[0048] Cooling is a prerequisite for mechanical compression, and the cooling mechanism ensures system stability. Parametric amplification, induced by Duffing nonlinearity and quadratic optomechanical coupling, is the source of mechanical compression between the two mechanical oscillators. Ultimately, the combined effects of optomechanical cooling and parametric amplification enable simultaneous quantum compression of two mechanical oscillators without destabilizing the system.
[0049] Figure 2 The paper shows how the displacement-variance fluctuations of the dual mechanical modes change with the frequency detuning between the first strong pump field and the first optical cavity under the influence of different thermal noises. It can be seen that under the drive of the strong pump field, when the system is in a relatively low temperature environment, adjusting the frequency detuning between the strong pump field and the optical cavity mode can effectively achieve cooling of the two mechanical oscillators by means of photomechanical coupling. Combined with the parametric amplification effect induced by Duffing nonlinearity and quadratic photomechanical coupling, strong quantum compression of the dual mechanical oscillators can be generated, breaking the 3dB limit. When the system is at a higher temperature, the ambient temperature will have a negative impact on the mechanical compression, but the mechanical compression of the dual mechanical oscillators generated by this method can still exist in a specific frequency detuning region, that is, the mechanical compression of the dual mechanical oscillators generated by the method of the present invention has a certain robustness to the thermal noise of the environment.
[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should all be included in the scope of the claims of the present invention.
Claims
1. A light force system, characterized in that: The system consists of two Fabry-Perot cavities, springs, a partially reflective elastic film, capacitors, and two strong pump fields; The left cavity mirror I of the first Fabry-Perot cavity is a partially transmissive fixed mirror, and the right cavity mirror I is a movable mirror capable of total reflection, which is connected to a spring. In the second Fabry-Perot cavity, an elastic film is placed in the exact center of the cavity; the elastic film is coupled to the right cavity mirror I in the first Fabry-Perot cavity through a capacitor as a medium; two strong pump fields are injected into the two Fabry-Perot cavities respectively to drive the movement of photons.
2. The optical force system according to claim 1, wherein: After the first strong pump field drives the first Fabry-Perot cavity, the photons in the cavity will move back and forth. The photons with momentum hit the movable mirror, generating mechanical displacement. The movable mirror acts as the first mechanical oscillator q1 and vibrates, changing the cavity length and causing the resonant frequency of the cavity to change. At the same time, the mechanical oscillator q1 is a mechanical oscillator with Duffing nonlinearity.
3. The optical force system according to claim 2, wherein: The elastic film divides the second Fabry-Perot cavity into two left and right sub-cavities, serving as the second mechanical oscillator q2; the first sub-cavity is composed of a fixed left-side cavity mirror II and an elastic film, and the second sub-cavity is composed of a fixed right-side cavity mirror II and an elastic film; after the second strong pump field is incident on the second Fabry-Perot cavity, it drives the vibration of the elastic film, changes the cavity length of the two sub-cavities, causes the optomechanical coupling of the two sub-cavities to change, and ultimately generates a quadratic optomechanical coupling between the cavity field and the film.
4. The optical force system according to claim 3, wherein: The second mechanical oscillator q2 exchanges energy with the first mechanical oscillator q1 having Duffing nonlinearity through the capacitor C as a medium, thereby achieving mechanical coupling.
5. The optical force system according to any one of claims 2 to 4, characterized in that: Based on this system, quantum compression of two mechanical oscillators is achieved simultaneously. The specific method is as follows: Two continuous-wave single-frequency solid-state lasers output two strong pump fields, which are injected into the left and right Fabry-Perot cavities respectively; Frequency is ω L1 The first strong pump field is incident on the first Fabry-Perot cavity, stimulating the mechanical displacement of the right cavity mirror I, affecting the change of the cavity length, and realizing the single-photon linear optical force coupling between the cavity field in the first cavity and the first mechanical oscillator q1; Frequency is ω L2 After the second strong pump field is incident on the second Fabry-Perot cavity, it excites the mechanical vibration of the elastic film, and finally generates a quadratic optical-mechanical coupling between the second cavity field and the second mechanical oscillator q2; Using a linearized approximation method, under the conditions of weak single-photon linear optical coupling and even weaker single-photon quadratic optical coupling, the steady-state amplitude of the cavity field is not affected by the optical coupling and is independently controlled by the driving frequency and phase of the second strong pump field. The driving phase of the two pump fields is adjusted so that the steady-state amplitudes of the two cavity fields are both real numbers, and the optomechanical coupling under the action of the strong pump field is further amplified. Finally, the existence of Duffing nonlinearity and quadratic optomechanical coupling produces parametric amplification of the right cavity mirror I and the second mechanical oscillator q2, respectively.
6. The optical force system according to claim 5, wherein: The mechanical modes of the two mechanical oscillators are compressed and transformed respectively. Under the compression transformation phenomenon, the resonance frequencies of the two compression mechanical modes are made equal, producing a "beam splitter" type mechanical effect. By controlling the frequency detuning between the first strong pump field and the resonance frequency of the first Fabry-Perot cavity, the red detuned sideband optical mode in the first Fabry-Perot cavity and the mechanical mode of the first mechanical oscillator resonate simultaneously.
7. The optical force system according to claim 5, wherein: The photomechanical coupling generated by the driving of the first strong pump field provides a cooling path for the first mechanical oscillator, while the mechanical coupling between the two mechanical oscillators extracts thermal excitation from the second mechanical oscillator to achieve the purpose of cooling the second mechanical oscillator.
8. The optical force system according to claim 7, wherein: Quantum compression of two mechanical oscillators is achieved simultaneously through the combined effects of photomechanical cooling and parametric amplification.