Low temperature, low vibration system for ion traps

Abstract

The application discloses a low-temperature and low-vibration system for an ion trap, which comprises an optical platform for mounting an optical system, a refrigerator located below the optical platform and connected with the ground through a first vibration reduction base to effectively absorb the vibration of the refrigerator, and a cold head structure arranged upwardly; a vacuum pipeline comprising a low-temperature coupling section, a flexible vibration isolation section and a working section which are sequentially arranged and connected and jointly enclose a closed vacuum chamber, the low-temperature coupling section is connected with the refrigerator and encircles at least part of the outer side of the cold head structure, and at least part of the working section penetrates the optical platform upwardly and is connected with the optical platform; and a sample support base arranged in the working section and located above the optical platform and connected with the cold head structure through a flexible vibration isolation heat conduction structure. The low-temperature and low-vibration system for the ion trap can effectively isolate the vibration and has a more remarkable vibration isolation effect.

Description

Technical Field

[0001] This invention relates to the field of optical experimental technology, and in particular to a low-temperature, low-vibration system for ion traps. Background Technology

[0002] In scientific research activities in fields such as optics, atomic physics, and quantum mechanics, ultra-low temperature and ultra-vacuum environments are often required to ensure accurate experimental results.

[0003] Currently, there are two main methods for obtaining ultra-low temperatures: one is liquid helium immersion, which is quiet and efficient, but consumes a large amount of liquid helium and is costly; the other is cyclic refrigeration, in which the refrigerator inevitably vibrates during operation, causing the experimental sample to vibrate, which has a certain impact on the experimental results. For example, it affects the collimation of the laser and the trapped ions, and affects the efficiency of laser manipulation of ions. For quantum computing, the vibration of the ion trap can lead to decoherence between qubits.

[0004] For example, patent application number CN201910570256.9, entitled "Ultra-low Temperature Vibration Isolation System for Quantum Simulation and Computation Chip Ion Trap Experiments," discloses a structure that utilizes a refrigerator for cyclic cooling. However, due to the high center of gravity of the refrigerator and vacuum chamber, braking is difficult to effectively suppress. At the same time, due to the torque amplification effect, it may generate even greater vibrations. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a low-temperature, low-vibration system for ion traps that can effectively isolate vibration.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] Low-temperature, low-vibration systems for ion traps include:

[0008] Optical platform;

[0009] A refrigeration unit, located below the optical platform and connected to the ground via a first vibration damping substrate, includes an upward-facing cold head structure;

[0010] The vacuum pipeline includes a cryogenic coupling section, a flexible vibration isolation section, and a working section that are arranged and connected in sequence to form a closed vacuum chamber. The cryogenic coupling section is connected to the refrigerator and surrounds at least a portion of the cold head structure. At least a portion of the working section passes upward through the optical platform and is connected to the optical platform.

[0011] The sample support substrate is located within the working section and is connected to the cold head structure via a flexible vibration isolation and heat conduction structure.

[0012] Furthermore, it also includes a support platform located below the optical platform and used for connection to the ground, the first vibration damping substrate is disposed on the support platform, and the top of the support platform is provided with a through hole that runs through its upper and lower ends and allows the body of the refrigerator to enter.

[0013] Furthermore, the optical platform is provided with a second vibration damping substrate for connection with the ground.

[0014] Furthermore, the cold head structure includes a primary cold head and a secondary cold head arranged sequentially from bottom to top, with at least a portion of the primary cold head and the secondary cold head located within the low-temperature coupling section;

[0015] The sample support substrate includes mounting platforms and sample cooling platforms arranged sequentially from bottom to top. The mounting platforms are used to mount a heat-conducting cover on the sample.

[0016] The flexible vibration isolation and heat conduction structure includes a first flexible heat conduction component and a second flexible heat conduction component. The first flexible heat conduction component connects the primary cold head and the mounting platform, and the second flexible heat conduction component connects the secondary cold head and the sample cold stage.

[0017] Furthermore, it also includes:

[0018] A cold shield is disposed within the vacuum chamber, between and connected to the first-stage cold head and the first flexible heat-conducting component, and surrounds the outside of the first-stage cold head and the second-stage cold head.

[0019] A first thermal insulation support sleeve is disposed in the vacuum chamber, with its first end connected to the mounting platform and its second end close to the cold shield, and connected to the inner wall of the vacuum pipe and encircling at least a portion of the outer side of the first flexible thermal conductive element.

[0020] A second thermal insulation support sleeve is disposed in the vacuum chamber, with its first end connected to the mounting stage and its second end connected to the sample cold stage, and it surrounds at least a portion of the outer side of the second flexible thermal conductive element.

[0021] Furthermore, the second end of the first thermal insulation support sleeve is fitted onto the outer side of the end of the cold shield near the mounting platform.

[0022] Furthermore, the first end of the second thermal insulation support sleeve passes through the mounting platform and is close to the cold shield, and the first end of the second thermal insulation support sleeve is located inside the first thermal insulation support sleeve.

[0023] Furthermore, both the first thermal insulation support sleeve and the second thermal insulation support sleeve include a first thermal insulation cylinder and a second thermal insulation cylinder connected to the first thermal insulation cylinder and encircling at least a portion of the outside of the first thermal insulation cylinder.

[0024] Furthermore, the first insulation cylinder and the second insulation cylinder are arranged apart from each other.

[0025] Furthermore, both the first thermal insulation support sleeve and the second thermal insulation support sleeve are made of stainless steel or G10.

[0026] Furthermore, the cryogenic coupling section is equipped with a vacuum pump that communicates with the vacuum chamber.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] The low-temperature, low-vibration system for ion traps of the present invention can efficiently transfer the cooling energy of the cold head structure to the sample support substrate using a flexible vibration-damping and heat-conducting structure, enabling the sample support substrate to obtain an ultra-low temperature environment. Furthermore, by connecting the refrigerator to the first vibration-damping substrate, and the low-temperature coupling section to the refrigerator, with the working section located on the optical platform, the refrigerator and the low-temperature coupling section are physically separated and independently installed. This significantly reduces the vibration impact on the sample support substrate located within the working section. Simultaneously, since the refrigerator and the low-temperature coupling section are located below the optical platform, this structural design lowers the center of gravity of both the refrigerator and the low-temperature coupling section. Based on this, the combined use of the flexible vibration-damping and heat-conducting structure, the flexible vibration-damping section, and the first vibration-damping substrate effectively suppresses the vibration of the refrigerator, resulting in a significant vibration isolation effect. Additionally, because the refrigerator is located below the optical platform, it does not increase the lateral dimensions of the low-temperature, low-vibration system for ion traps, making the system more compact and requiring less floor space. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the low-temperature, low-vibration system for an ion trap according to the present invention;

[0030] Figure 2 This is a front view of the cryogenic, low-vibration system for an ion trap according to the present invention.

[0031] Figure 3 for Figure 2 The cross-sectional view along the AA direction is shown in the cryogenic, low-vibration system for an ion trap.

[0032] Figure 4 for Figure 3 Enlarged view of section A in the image;

[0033] Figure 5 This is a schematic diagram of the assembly of the sample support substrate, the first thermal insulation support sleeve, and the second thermal insulation support sleeve in the low-temperature, low-vibration system for an ion trap according to the present invention.

[0034] Figure 6 for Figure 5 A cross-sectional view along the BB direction.

[0035] In the diagram: 10, optical platform; 20, support platform; 30, refrigerator; 31, cold head structure; 311, primary cold head; 312, secondary cold head; 40, vacuum pipe; 41, low-temperature coupling section; 42, flexible vibration isolation section; 43, working section; 50, first vibration damping substrate; 60, sample support substrate; 61, mounting platform; 62, sample cold stage; 70, flexible vibration isolation and heat conduction structure; 71, first flexible heat conduction component; 72, second flexible heat conduction component; 80, second vibration damping substrate; 90, cold shield; 100, first thermal insulation support sleeve; 101, first thermal insulation cylinder; 102, second thermal insulation cylinder; 200, second thermal insulation support sleeve; 300, vacuum pump. Detailed Implementation

[0036] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0037] See Figures 1-3 This illustration shows a preferred embodiment of a low-temperature, low-vibration system for an ion trap, comprising: an optical platform 10 for mounting an optical system; a refrigerator 30 located below the optical platform 10 and connected to the ground via a first vibration-damping substrate 50 to effectively absorb vibrations from the refrigerator 30, including a cold head structure 31 positioned upwards within a vacuum chamber; a vacuum conduit 40 comprising a low-temperature coupling section 41, a flexible vibration-damping section 42, and a working section 43 arranged sequentially from bottom to top and connected to form a closed vacuum chamber, wherein the low-temperature coupling section 41 is connected to the refrigerator 30 and surrounds at least a portion of the cold head structure 31 on the outside, and at least a portion of the working section 43 extends upwards through the optical platform 10 and is connected to the optical platform 10; and a sample support substrate 60 located within the working section 43 and above the optical platform 10, connected to the cold head structure 31 via a flexible vibration-damping and heat-conducting structure 70.

[0038] The low-temperature, low-vibration system for ion traps of the present invention can efficiently transfer the cooling energy of the cold head structure 31 to the sample support substrate 60 using the flexible vibration-damping and heat-conducting structure 70, thereby providing the sample support substrate 60 with an ultra-low temperature environment. Furthermore, by connecting the refrigerator 30 and the first vibration-damping substrate 50, and connecting the low-temperature coupling section 41 and the refrigerator 30, with the working section 43 positioned on the optical platform 10, the refrigerator 30 and the low-temperature coupling section 41 are physically separated and independently installed. This significantly reduces the vibration impact on the sample support substrate 60 located within the working section 43. Simultaneously, due to… The refrigerator 30 and the cryogenic coupling section 41 are located below the optical platform 10. Therefore, this structural arrangement lowers the center of gravity of both the refrigerator 30 and the cryogenic coupling section 41. Based on this, the combined use of the flexible vibration isolation and heat conduction structure 70, the flexible vibration isolation section 42, and the first vibration damping substrate 50 can effectively suppress the vibration of the refrigerator 30, resulting in a significant vibration isolation effect. In addition, since the refrigerator 30 is located below the optical platform 10, it does not increase the lateral dimension of the cryogenic low-vibration system originally used for the ion trap, making the structure of the cryogenic low-vibration system originally used for the ion trap more compact and occupying less space.

[0039] See Figures 1-3 In this embodiment, the low-temperature, low-vibration system for the ion trap also includes a support platform 20 located below the optical platform 10 and used for connection to the ground. The first vibration damping base 50 is disposed on the support platform 20. The top of the support platform 20 is provided with a through hole that runs through its upper and lower ends and allows the body of the refrigerator 30 to enter. The setting of the support platform 20 can effectively reduce the height of the first vibration damping base 50, which is beneficial to reduce the material of the first vibration damping base 50 and thus reduce costs. At the same time, it can also lower the center of gravity of the refrigerator 30, making the installation of the refrigerator 30 more stable and reliable, thereby further suppressing the vibration of the refrigerator 30.

[0040] To facilitate the installation of the first vibration damping base 50, in this embodiment, the first vibration damping base 50 is disposed on the outer wall of the low-temperature coupling section 41, that is, the first vibration damping base 50 is indirectly disposed on the refrigerator 30.

[0041] See Figures 1-3 In this embodiment, the optical platform 10 is provided with a second vibration damping base 80 for connection with the ground, so as to further reduce the vibration of the refrigerator 30 and the vibration isolation effect is more significant.

[0042] In this embodiment, the refrigerator 30 is specifically a GM refrigerator. In other embodiments, the refrigerator 30 may also be a JT refrigerator or a PT refrigerator.

[0043] See Figures 1-4In this embodiment, the cold head structure 31 includes a primary cold head 311 and a secondary cold head 312 arranged sequentially from bottom to top, and at least a portion of the primary cold head 311 and the secondary cold head 312 are located within the low-temperature coupling section 41.

[0044] The sample support substrate 60 includes a mounting platform 61 and a sample cold stage 62 arranged sequentially from bottom to top. The mounting platform 61 is used to mount a heat-conducting cover on the sample. The heat-conducting cover is a cold screen structure.

[0045] The flexible vibration isolation and heat conduction structure 70 includes a first flexible heat conduction element 71 and a second flexible heat conduction element 72. The first flexible heat conduction element 71 connects the first-stage cold head 311 and the mounting platform 61 to transfer the cooling capacity of the first-stage cold head 311 to the mounting platform 61, and then transfers the cooling capacity of the first-stage cold head 311 to the heat conduction cover through the mounting platform 61. At the same time, it effectively isolates the vibration of the refrigerator 30. The second flexible heat conduction element 72 connects the second-stage cold head 312 and the sample cold stage 62 to transfer the cooling capacity of the second-stage cold head 312 to the sample cold stage 62, and then transfers the cooling capacity to the sample through the sample cold stage 62. At the same time, it effectively isolates the vibration of the refrigerator 30. Thus, the sample obtains an ultra-low temperature environment, while effectively suppressing the vibration of the refrigerator 30.

[0046] Specifically, in this embodiment, both the mounting stage 61 and the sample cooling stage 62 are made of metal with high thermal conductivity, such as any one of oxygen-free copper, silver, gold, etc.

[0047] In this embodiment, both the first flexible heat-conducting element 71 and the second flexible heat-conducting element 72 are copper braids with good thermal conductivity, so that the sample support substrate 60 can obtain an ultra-low temperature environment. Of course, in other embodiments, the first flexible heat-conducting element 71 and the second flexible heat-conducting element 72 can be silver braids or gold braids, but the cost is higher.

[0048] See Figure 4 The cryogenic, low-vibration system for ion traps also includes:

[0049] The cold shield 90 is located inside the vacuum chamber and is positioned between and connected to the first-stage cold head 311 and the first flexible heat-conducting element 71. It also surrounds the outside of the first-stage cold head 311 and the second-stage cold head 312. This allows for the efficient transfer of the cooling capacity of the first-stage cold head 311 to the mounting platform 61. Since it is located outside the second-stage cold head 312 and its temperature is the same as that of the first-stage cold head 311, which is higher than that of the second-stage cold head 312, the temperature difference between the second-stage cold head 312 and the inner wall of the vacuum pipe 40 can be reduced. This reduces the radiative heat transfer of the second-stage cold head 312 and thus reduces the cooling capacity loss of the second-stage cold head 312.

[0050] The first heat-insulating support sleeve 100 is disposed in the vacuum chamber. The first end is connected to the mounting platform 61, and the second end is close to the cold screen 90. It is connected to the inner wall of the vacuum pipe 40 and wraps around at least part of the outer side of the first flexible heat-conducting element 71. The first heat-insulating support sleeve 100 can reliably fix the mounting platform 61 to the vacuum pipe 40 while also playing a heat-insulating role, that is, preventing heat conduction and effectively avoiding cold loss.

[0051] The second thermal insulation support sleeve 200 is located in the vacuum chamber. Its first end is connected to the mounting stage 61, and its second end is connected to the sample cold stage 62. It also surrounds at least part of the outer side of the second flexible heat-conducting element 72. The second thermal insulation support sleeve 200 can reliably fix the sample cold stage 62 while also providing thermal insulation, i.e., preventing heat conduction and effectively avoiding heat loss. In addition, since the vacuum pipe 40, the mounting stage 61, and the sample cold stage 62, which have different temperatures, are connected in sequence through the first thermal insulation support structure and the second thermal insulation support structure, thermal short circuits can be effectively avoided, thereby ensuring that the sample cold stage 62 can obtain an ultra-low temperature environment of 4K.

[0052] See Figure 4 In this embodiment, the second end of the first thermal insulation support sleeve 100 is sleeved on the outer side of the end of the cold screen 90 near the mounting platform 61. This makes the overall length of the first thermal insulation support sleeve 100 longer and the outer surface area larger, which can further increase the resistance to heat conduction and make the thermal insulation effect more significant.

[0053] See Figure 4 In this embodiment, the first end of the second thermal insulation support sleeve 200 passes through the mounting platform 61 and is close to the cold screen 90, and the first end of the second thermal insulation support sleeve 200 is located inside the first thermal insulation support sleeve 100. This makes the overall length of the second thermal insulation support sleeve 200 longer and the outer surface area larger, which can further increase the resistance to heat conduction and make the thermal insulation effect more significant.

[0054] See Figures 5-6 In this embodiment, both the first thermal insulation support sleeve 100 and the second thermal insulation support sleeve 200 include a first thermal insulation cylinder 101 and a second thermal insulation cylinder 102 connected to the first thermal insulation cylinder 101 and surrounding at least a portion of the outer side of the first thermal insulation cylinder 101. Thus, the double-layered first thermal insulation support sleeve 100 and the second thermal insulation support sleeve 200 have better structural strength, can reliably support the mounting platform 61 and the sample cold platform 62, and at the same time, the thermal insulation effect is also more significant.

[0055] In this embodiment, the first insulation cylinder 101 and the second insulation cylinder 102 are arranged apart to avoid increasing the thickness of both the first insulation cylinder 101 and the second insulation cylinder 102, thereby reducing the heat conduction area and achieving a better insulation effect.

[0056] In this embodiment, both the first thermal insulation support sleeve 100 and the second thermal insulation support sleeve 200 are made of stainless steel, which has high thermal resistance and can provide good structural support. In other embodiments, both the first thermal insulation support sleeve 100 and the second thermal insulation support sleeve 200 can be made of G10.

[0057] In this embodiment, the wall thickness of both the first insulation cylinder 101 and the second insulation cylinder 102 is 0.3mm-0.7mm to ensure reliable support for the mounting platform 61 and the sample cold platform 62. At the same time, the wall thickness of both the first insulation support sleeve 100 and the second insulation support sleeve 200 is made as thin as possible to reduce the heat conduction area and further improve the insulation effect.

[0058] See Figure 3 In this embodiment, a vacuum pump 300 connected to the vacuum chamber is provided on the low-temperature coupling section 41. The vacuum pump 300 is used to obtain a super vacuum in the vacuum chamber. At the same time, since the vacuum pump 300 is located on the low-temperature coupling section 41, the center of gravity of the vacuum pipe 40 can be effectively reduced, thus making the vibration isolation effect more significant.

[0059] In this embodiment, the working section 43 includes an electrical section and a laser section arranged sequentially from bottom to top. The electrical section is used to connect with the electrical feedthrough, which is used to conduct electrical connections between the inside and outside of the vacuum chamber. The laser section is used to provide an optical channel for the sample.

[0060] The method of using the low-temperature, low-vibration system for ion traps of the present invention is as follows:

[0061] First, the laser segment needs to be turned on. Then, the sample is fixed on the sample cold stage 62. At the same time, electrical connections are made and the laser window on the laser segment is collimated and adjusted. Finally, the heat conduction cover is installed on the mounting stage 61 to provide radiation isolation for the sample. Finally, the laser segment is turned off.

[0062] Next, the vacuum chamber is leak-tested to ensure that the vacuum leakage rate is within an acceptable range;

[0063] Next, the experimental optical system was installed and debugged on the optical platform 10, and the vacuum chamber was baked and degassed. Then, the vacuum chamber was vacuumed to obtain a supervacuum.

[0064] After the vacuum chamber has cooled naturally, turn on the refrigerator 30 to cool it down until the sample temperature drops to the target temperature, then the experiment can begin.

[0065] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A low-temperature, low-vibration system for ion traps, characterized in that, include: Optical platform (10); A refrigeration unit (30) is located below the optical platform (10) and connected to the ground via a first damping substrate (50), including an upward-facing cold head structure (31); The vacuum pipe (40) includes a low-temperature coupling section (41), a flexible vibration isolation section (42), and a working section (43) arranged in sequence and connected in sequence to form a closed vacuum chamber. The low-temperature coupling section (41) is connected to the refrigerator (30) and surrounds at least a portion of the cold head structure (31) on the outside. At least a portion of the working section (43) passes upward through the optical platform (10) and is connected to the optical platform (10). The sample support substrate (60) is located within the working section (43) and is connected to the cold head structure (31) via a flexible vibration-damping and heat-conducting structure (70). Among them, the refrigerator (30) and the first vibration damping base (50) are connected to the ground, the low temperature coupling section (41) is connected to the refrigerator (30), the working section (43) is set on the optical platform (10), and the refrigerator (30) and the low temperature coupling section (41) are located below the optical platform (10), which lowers the center of gravity of the refrigerator (30). In addition, the refrigerator (30), the first vibration damping base (50), the flexible vibration isolation section (42) and the flexible vibration isolation heat conduction structure (70) are arranged in sequence from bottom to top in space to transfer the cold energy of the cold head structure (31) to the sample support base (60), so that the vibration of the refrigerator (30) is attenuated in multiple stages before being transmitted to the sample support base (60).

2. The cryogenic, low-vibration system for an ion trap as described in claim 1, characterized in that, It also includes a support platform (20) located below the optical platform (10) and used for connection to the ground. The first vibration damping base (50) is provided on the support platform (20). The top of the support platform (20) is provided with a through hole that runs through its upper and lower ends and allows the body of the refrigerator (30) to enter.

3. The cryogenic, low-vibration system for an ion trap as described in claim 1, characterized in that, The optical platform (10) is provided with a second vibration damping base (80) for connection with the ground.

4. The cryogenic, low-vibration system for an ion trap as described in claim 1, characterized in that, The cold head structure (31) includes a primary cold head (311) and a secondary cold head (312) arranged sequentially from bottom to top, with at least a portion of the primary cold head (311) and the secondary cold head (312) located within the low-temperature coupling section (41); The sample support substrate (60) includes a mounting platform (61) and a sample cooling platform (62) arranged sequentially from bottom to top. The mounting platform (61) is used to mount a heat-conducting cover on the sample. The flexible vibration isolation and heat conduction structure (70) includes a first flexible heat conduction element (71) and a second flexible heat conduction element (72). The first flexible heat conduction element (71) connects the first-stage cold head (311) and the mounting platform (61), and the second flexible heat conduction element (72) connects the second-stage cold head (312) and the sample cold stage (62).

5. The cryogenic, low-vibration system for an ion trap as described in claim 4, characterized in that, Also includes: A cold shield (90) is disposed in the vacuum chamber and is located between and connected to the first-stage cold head (311) and the first flexible heat-conducting element (71), and surrounds the outside of the first-stage cold head (311) and the second-stage cold head (312); The first thermal insulation support sleeve (100) is disposed in the vacuum chamber, with its first end connected to the mounting platform (61) and its second end close to the cold screen (90), and connected to the inner wall of the vacuum pipe (40) and wrapped around at least part of the outer side of the first flexible thermal conductive element (71). The second thermal insulation support sleeve (200) is disposed in the vacuum chamber, with its first end connected to the mounting stage (61) and its second end connected to the sample cold stage (62), and it surrounds at least a portion of the outer side of the second flexible thermal conductive element (72).

6. The cryogenic, low-vibration system for an ion trap as described in claim 5, characterized in that, The second end of the first thermal insulation support sleeve (100) is sleeved on the outer side of the end of the cold screen (90) near the mounting platform (61).

7. The cryogenic, low-vibration system for an ion trap as described in claim 5, characterized in that, The first end of the second thermal insulation support sleeve (200) passes through the mounting platform (61) and is close to the cold screen (90), and the first end of the second thermal insulation support sleeve (200) is located inside the first thermal insulation support sleeve (100).

8. The cryogenic, low-vibration system for an ion trap as described in claim 5, characterized in that, Both the first thermal insulation support sleeve (100) and the second thermal insulation support sleeve (200) include a first thermal insulation cylinder (101) and a second thermal insulation cylinder (102) connected to the first thermal insulation cylinder (101) and encircling at least a portion of the outside of the first thermal insulation cylinder (101).

9. The cryogenic, low-vibration system for an ion trap as described in claim 8, characterized in that, The first insulation cylinder (101) and the second insulation cylinder (102) are arranged apart from each other.

10. The cryogenic, low-vibration system for an ion trap as described in claim 5, characterized in that, Both the first thermal insulation support sleeve (100) and the second thermal insulation support sleeve (200) are made of stainless steel or G10.

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