Quantum storage devices and methods

Abstract

This disclosure provides a quantum storage device for the field of quantum information technology, comprising: a light generation unit for generating pump light required for an integrable storage unit, and for preparing polarized qubit photons to be stored, and outputting the pump light and polarized qubit photons to the integrable storage unit; an electrical generation unit for generating electrical pulse signals required for the integrable storage unit, and outputting the electrical pulse signals to the integrable storage unit; an integrable storage unit, fabricated on a rare-earth ion-doped crystal, for preparing a specific absorption band using pump light according to a specified storage scheme, and for realizing on-demand reading of polarized qubit photons according to the electrical pulse signals; and a polarization detection unit for detecting the polarization state of the photon echo generated by the stored polarized qubit photons.

Description

Technical Field

[0001] This disclosure relates to the field of quantum information technology, and in particular to a quantum storage device and method. Background Technology

[0002] In the field of quantum communication, photons experience varying degrees of loss during transmission in free space or optical fibers, making ultra-long-distance quantum communication difficult. To achieve quantum communication over distances exceeding 100 kilometers, quantum repeaters are a viable solution, and quantum memories are a core component of quantum repeaters. Integrating quantum memories can expand the number of channels, reduce memory size and device scale, and combined with integrated optical systems such as quantum chips, holds significant application and development potential. Polarization encoding is one of the important methods for encoding photons in the field of quantum information, but existing quantum memories, due to limitations in crystal energy level absorption, generally only support the storage of one polarization state. Summary of the Invention

[0003] The main objective of this disclosure is to provide a quantum storage device and method that can support the storage of arbitrary polarization states.

[0004] To achieve the above objectives, a first aspect of this disclosure provides a quantum storage device, comprising:

[0005] Light generation unit, electrical generation unit, integrable storage unit, and polarization analyzer unit;

[0006] The light generating unit is used to generate the pump light required for the integrable storage unit, and to prepare polarized bit photons to be stored, and to output the pump light and the polarized bit photons to the integrable storage unit.

[0007] The electrical generation unit is used to generate the electrical pulse signal required by the integrable storage unit and output the electrical pulse signal to the integrable storage unit.

[0008] The integrable storage unit is fabricated on a rare-earth ion-doped crystal and supports transmission of arbitrary polarization states. It is used to prepare a specific absorption band using the pump light according to a specified storage scheme, and to realize on-demand reading of the polarized bit photons according to the electrical pulse signal.

[0009] The polarization detection unit is used to detect the polarization state of the photon echo generated by the stored polarized bit photons.

[0010] In one embodiment, the light generating unit includes:

[0011] Laser, first acousto-optic modulator, second acousto-optic modulator, and polarization state preparation unit;

[0012] The laser is used to generate laser light with a linewidth within a specified range;

[0013] The first acousto-optic modulator is used to modulate the pump light required by the integrable memory cell according to the laser, and output the pump light to the integrable memory cell;

[0014] The second acousto-optic modulator is used to modulate the signal photon to be stored according to the laser and output the signal photon to the polarization state preparation unit;

[0015] The polarization state preparation unit is used to encode the signal photon into polarization bits to obtain the polarization bit photon to be stored, and output the polarization bit photon to the integrable storage unit.

[0016] In one embodiment, the integrable storage unit includes:

[0017] Electrical waveguides and optical waveguides;

[0018] The optical waveguide is used to confine the polarized bit photons;

[0019] The electrical waveguide is used to apply the electrical pulse signal to rare earth ions located in the optical waveguide to generate the localized electrical pulse signal.

[0020] In one embodiment, when the specified storage scheme is an electrically controlled atomic frequency comb scheme, the specific absorption band is the absorption band of the frequency comb structure, and the electrical pulse signal is a pulsed electric field signal;

[0021] When the specified storage scheme is a spin wave atomic frequency comb scheme, the specific absorption band is the absorption band of the frequency comb structure, and the electrical pulse signal is a radio frequency magnetic field signal;

[0022] When the specified storage scheme is a noiseless photon echo scheme, the specific absorption band is an isolated absorption band, and the electrical pulse signal is a radio frequency magnetic field signal.

[0023] In one embodiment, the polarization detection unit includes:

[0024] Wedge plates for specific wavelengths, quarter-wave plates for specific wavelengths, half-wave plates for specific wavelengths, and polarization beam splitting crystals for specific wavelengths.

[0025] The specific wavelength wedge is used to compensate for crystal birefringence and additional phase introduced during storage.

[0026] The half-wave plate and the quarter-wave plate of the specific wavelength are used together to project the polarization state of the photon echo generated by the stored photon to a horizontal polarization state.

[0027] The polarization beam splitter crystal is used for polarization detection, filtering out the horizontal polarization component in the echo photon, and finally incident into the single-photon detector for detection.

[0028] In one embodiment, the optical transitions of the rare-earth ion-doped crystal have consistent absorption depths for two orthogonal polarization components.

[0029] In one embodiment, the performance of the optical waveguide is independent of polarization, supporting transmission in any polarization state.

[0030] In one embodiment, the optical waveguide is disposed within a range of 20 micrometers from the surface of the rare-earth ion-doped crystal;

[0031] The electrical waveguide is disposed on the surface of the rare earth ion-doped crystal.

[0032] In one embodiment, the rare earth ion-doped crystal is an Eu:YSO crystal, wherein the Eu ions at substitution 2 in the Eu:YSO crystal... 7 F0- 5 The D0 level transition satisfies the condition that the two orthogonal polarization components have the same absorption depth.

[0033] In one embodiment, the rare-earth ion-doped crystal is placed in a low-temperature environment of about 3K, so that its optical transitions should have a long quantum coherence lifetime; further combined with a strong magnetic field working environment, its spin transitions should have a long quantum coherence lifetime.

[0034] A second aspect of this disclosure provides a storage method for a quantum storage device, characterized in that the storage device includes a light-generating unit, an electrical-generating unit, an integrable storage unit, and a polarization analyzer, wherein the integrable storage unit is fabricated on a rare-earth ion-doped crystal, and the method includes:

[0035] The pump light required for the integrable memory cell is generated using the light generation unit, and polarized bit photons to be stored are prepared, and the pump light and the polarized bit photons are output to the integrable memory cell.

[0036] The electrical pulse signal required by the integrable storage unit is generated using the electrical generation unit, and the electrical pulse signal is output to the integrable storage unit.

[0037] Using the integrable storage unit according to a specified storage scheme, a specific absorption band is prepared according to the pump light, and the polarized bit photons are read on demand according to the electrical pulse signal;

[0038] The polarization state of the photon echo generated by the stored polarization bit photons is detected using the polarization analyzer unit.

[0039] In one embodiment, when the specified storage scheme is an electrically controlled atomic frequency comb scheme, the specific absorption band is the absorption band of the frequency comb structure, and the electrical pulse signal is a pulsed electric field signal;

[0040] When the specified storage scheme is a spin wave atomic frequency comb scheme, the specific absorption band is the absorption band of the frequency comb structure, and the electrical pulse signal is a radio frequency magnetic field signal;

[0041] When the specified storage scheme is a noiseless photon echo scheme, the specific absorption band is an isolated absorption band, and the electrical pulse signal is a radio frequency magnetic field signal.

[0042] As can be seen from the above embodiments of this disclosure, the quantum storage device and method provided by this disclosure adopts an on-demand quantum storage method, which can realize the storage of polarized qubit photons. It can be used in long-distance quantum communication schemes such as quantum repeaters based on polarized qubit photons, and has the advantages of large-scale integration, high signal-to-noise ratio and ease of implementation. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this disclosure 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 this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 A schematic diagram of the structure of a quantum storage device provided in an embodiment of this disclosure;

[0045] Figure 2 A schematic diagram of the structure of a quantum storage device provided in an embodiment of this disclosure;

[0046] Figure 3 A schematic flowchart illustrating a storage method for a quantum storage device provided in an embodiment of this disclosure;

[0047] Figure 4 A schematic diagram of the storage time series of an electronically controlled atomic frequency comb scheme provided in one embodiment of this disclosure;

[0048] Figure 5 This disclosure provides a schematic diagram of the storage time series of an atomic frequency comb scheme based on spin waves, according to one embodiment. Detailed Implementation

[0049] To make the objectives, features, and advantages of this disclosure more apparent and understandable, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0050] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a quantum storage device provided in an embodiment of the present disclosure. The device includes:

[0051] Light generating unit 12, electrical generating unit 13, integrable storage unit 11 and polarization analyzer 14;

[0052] The light generating unit 12 is used to generate the pump light required for the integrable storage unit 11, and to prepare the polarized bit photons 1521 to be stored, and to output the pump light and the polarized bit photons 1521 to the integrable storage unit 11.

[0053] The electrical generation unit 13 is used to generate the electrical pulse signal required by the integrable storage unit 11 and output the electrical pulse signal to the integrable storage unit 11.

[0054] An integrable storage unit 11 is fabricated on a rare-earth ion-doped crystal 111 and supports transmission of arbitrary polarization states. It is used to prepare a specific absorption band using pump light according to a specified storage scheme and to realize on-demand reading of polarized bit photons 1521 according to electrical pulse signals.

[0055] The polarization analyzer 14 is used to detect the polarization state of the photon echo 1524 generated by the stored polarized bit photon 1521.

[0056] In this disclosure, the specified storage scheme should support on-demand quantum bit storage.

[0057] In one embodiment of this disclosure, such as Figure 2 As shown, the light generation unit 12 includes a laser 121, a first acousto-optic modulator 122, a second acousto-optic modulator 123, and a polarization state preparation unit 124;

[0058] Laser 121 is used to generate laser with a linewidth within a specified range;

[0059] The first acousto-optic modulator 122 is used to modulate the pump light required by the laser to the integrable memory cell 11 and output the pump light to the integrable memory cell 11.

[0060] The second acousto-optic modulator 123 is used to modulate the signal photon to be stored according to the laser and output the signal photon to the polarization state preparation unit 124.

[0061] The polarization state preparation unit 124 is used to encode the signal photon into polarization bits to obtain the polarization bit photon 1521 to be stored, and output the polarization bit photon 1521 to the integrable storage unit 11.

[0062] In this disclosure, the linewidth can be below 10kHz within a specified range.

[0063] In one example of this disclosure, the first acousto-optic modulator 122 may be selected as an acousto-optic modulator with a center frequency of 200 MHz. The second acousto-optic modulator 123 is selected as an acousto-optic modulator with a center frequency of 200 MHz. The polarized bit photon 1521 modulated by the second acousto-optic modulator 123 has an optical field frequency of 200 MHz.

[0064] In one embodiment of this disclosure, the polarization state preparation unit 124 includes a polarization beam-splitting crystal, a half-wave plate, and a quarter-wave plate. The polarization beam-splitting crystal is used for polarization, allowing single-polarized light to pass through and calibrating the photon to be in a horizontal polarization state (H state). The half-wave plate and quarter-wave plate are used to encode the quantum state of the input photon.

[0065] Among them, a half-wave plate at 0 degrees and a quarter-wave plate at 0 degrees are in the H state; a half-wave plate at 45 degrees and a quarter-wave plate at 0 degrees are in the vertical polarization state (V state); a half-wave plate at 22.5 degrees and a quarter-wave plate at 45 degrees are in the H+V state; and a half-wave plate at 22.5 degrees and a quarter-wave plate at 0 degrees are in the H+iV state.

[0066] In one embodiment of this disclosure, the electrical generation unit 13 may be an arbitrary waveform generator or a vector microwave signal source, used to generate electrical pulse signals required by the integrable storage unit 11.

[0067] In one embodiment of this disclosure, such as Figure 2 As shown, the integrable storage unit 11 includes an electrical waveguide 112 and an optical waveguide 113. The optical waveguide 113 is used to confine polarized bit photons 1521, and the electrical waveguide 112 is used to apply an electrical pulse signal to rare earth ions located in the optical waveguide 113 to generate a local electrical pulse signal.

[0068] In one embodiment of this disclosure, the optical transitions of the rare-earth ion-doped crystal 111 have consistent absorption depths for two orthogonal polarization components. This consistency can be substantially consistent; one option for the rare-earth ion-doped crystal 111 is an Eu:YSO crystal, where the Eu ions at substitution 2 meet the absorption requirements for the 580 nm transition.

[0069] In one embodiment of this disclosure, an optical waveguide 113 is disposed within a 20-micrometer range from the surface of the rare-earth ion-doped crystal 111; an electrical waveguide 112 is disposed on the surface of the rare-earth ion-doped crystal 111.

[0070] In one example of this disclosure, the optical waveguide 113 can be a type III waveguide written directly by a femtosecond laser, supporting photon transmission in any polarization state. The electrical waveguide 112 can be composed of two parallel metal strips, fabricated on the surface of a rare-earth ion-doped crystal 111 by ultraviolet lithography and electron beam evaporation. The spacing between the electrical waveguide 112 and the optical waveguide 113 is selected in the range of 10µm-100µm.

[0071] In this disclosure, the integrable memory cell 11 operates at a low temperature of approximately 3K, enabling optical transitions to possess long quantum coherence lifetimes. Furthermore, the strong magnetic field environment further enhances the long quantum coherence lifetime of its spin transitions. Specifically, the integrable memory cell 11 can be placed within a cryogenic chamber for operation. The cryogenic chamber is set to a specific operating temperature of 3K, as mentioned above, and can be cooled using a liquid helium-free compressor.

[0072] In this disclosure, the rare earth ion-doped crystal 111 is purified using an isotope at a concentration of 0.1%. 151 Eu 3+ The following explanation uses a 12mm long doped YSO crystal as an example. The rare-earth ion-doped crystal 111 used for storage utilizes... 151 Eu ions at substitutional position 2 in Eu:YSO crystals 7 F0- 5 The D0 level transition exhibits absorption depths with negligible differences for the two orthogonal polarization components. For storage control procedures, please refer to [link / reference]. Figure 3 The first acousto-optic modulator 122 modulates the laser into a first sweep pulse 1525 required by the storage unit 11 to initialize the energy level, and a second sweep pulse 1526 to prepare an atomic frequency comb. The second acousto-optic modulator 123 modulates signal photons and outputs them to the polarization state preparation unit 124. The polarization state preparation unit 124 encodes these photons into polarization bit photons 1521, which are then output to the integrable storage unit 11. The atomic frequency comb can emit photon echoes 1524 at a preset time T. The electrical generation unit 13 generates a first electrical pulse 1522 and a second electrical pulse 1523. The first electrical pulse 1522 is incident at time T / 2, and the second electrical pulse 1523 is incident at 3T / 2, 5T / 2, ..., with the corresponding signal photons 1524 emitting at 2T, 3T, ..., thus achieving on-demand reading. Finally, the signal photons are incident on the polarization analyzer 14.

[0073] In one embodiment of this disclosure, the polarization analyzer 14 includes: a wedge plate of a specific wavelength, a quarter-wave plate of a specific wavelength, a half-wave plate of a specific wavelength, and a polarization beam splitter crystal of a specific wavelength.

[0074] Wedges with specific wavelengths are used to compensate for crystal birefringence and additional phase introduced during storage.

[0075] A half-wave plate of a specific wavelength and a quarter-wave plate of a specific wavelength are used together to project the polarization state of the photon echo 1524 generated by the stored photons to the H state.

[0076] Polarization beam splitter crystals are used for polarization analysis, filtering out the H-state component in the echo photons, and finally incident them into a single-photon detector for detection.

[0077] Among them, a half-wave plate at 0 degrees and a quarter-wave plate at 0 degrees project the echo photons of the H state to the H state; a half-wave plate at 45 degrees and a quarter-wave plate at 0 degrees project the echo photons of the V state to the H state; a half-wave plate at 22.5 degrees and a quarter-wave plate at 45 degrees project the echo photons of the H+V state to the H state; and a half-wave plate at 22.5 degrees and a quarter-wave plate at 0 degrees project the echo photons of the H+iV state to the H state.

[0078] In one embodiment of this disclosure, the polarization state H of the signal photon is aligned with the b-axis of the YSO crystal, and the polarization state V is aligned with the D1-axis of the YSO crystal. Birefringence does not occur in these two axes. The polarization state of the pump light is not required in principle, but here it is aligned with the D1-axis of the YSO crystal.

[0079] In one embodiment of this disclosure, when the specified storage scheme is an electrically controlled atomic frequency comb scheme, the specific absorption band is the absorption band of the frequency comb structure, and the electrical pulse signal is a pulsed electric field signal; when the specified storage scheme is a spin wave atomic frequency comb scheme, the specific absorption band is the absorption band of the frequency comb structure, and the electrical pulse signal is a radio frequency magnetic field signal; when the specified storage scheme is a noiseless photon echo scheme, the specific absorption band is the absorption band of an isolated structure, and the electrical pulse signal is a radio frequency magnetic field signal.

[0080] Please see Figure 3 , Figure 3 This is a schematic flowchart of a storage method for a quantum storage device according to an embodiment of the present disclosure. The quantum storage device includes a light-generating unit 12, an electrical-generating unit 13, an integrable storage unit 11, and a polarization analyzer 14. The integrable storage unit 11 is fabricated on a rare-earth ion-doped crystal 111. Specifically, it can be... Figure 1 The quantum storage device shown, the method includes:

[0081] S301, using the light generating unit 12 to generate the pump light required for the integrable storage unit 11, and preparing the polarized bit photon 1521 to be stored, and outputting the pump light and the polarized bit photon 1521 to the integrable storage unit 11.

[0082] S302. The electrical pulse signal required by the integrable storage unit 11 is generated by the electrical generation unit 13, and the electrical pulse signal is output to the integrable storage unit 11.

[0083] S303. Using the integrable storage unit 11 according to the specified storage scheme, a specific absorption band is prepared according to the pump light, and the polarized bit photon 1521 is read on demand according to the electrical pulse signal.

[0084] S304. The polarization state of the photon echo 1524 generated by the stored polarization bit photon 1521 is detected by the polarization analyzer 14.

[0085] In one embodiment of this disclosure, when the specified storage scheme is an electrically controlled atomic frequency comb scheme, the specific absorption band is the absorption band of the frequency comb structure, and the electrical pulse signal is a pulsed electric field signal; when the specified storage scheme is a spin wave atomic frequency comb scheme, the specific absorption band is the absorption band of the frequency comb structure, and the electrical pulse signal is a radio frequency magnetic field signal; when the specified storage scheme is a noiseless photon echo scheme, the specific absorption band is the absorption band of an isolated structure, and the electrical pulse signal is a radio frequency magnetic field signal.

[0086] When an electrically controlled atomic frequency comb scheme is selected, the stored time series is as follows: Figure 4 The specific operation steps are as follows: the pump 1525 generated by the light generation unit 12 prepares an atomic frequency comb in the integrable storage unit 11; the light generation unit 12 generates a signal photon 1521 and inputs it into the integrable storage unit 11; the electric generation unit 13 generates a first pulse electric field 1522 and inputs it into the integrable storage unit 11; the electric generation unit 13 generates a second pulse electric field 1523 and inputs it into the integrable storage unit 11. The second pulse electric field input 1523 is required to be a pulse with the same duration and opposite direction as the first pulse electric field input 1522; the polarization detection unit 14 reads out the photon polarization state 1524.

[0087] When choosing the spin wave atomic frequency comb scheme, the stored time series is as follows: Figure 5The specific operation steps are as follows: the light generation unit 12 generates pump light 1626 to prepare an atomic frequency comb in the integrated storage unit 11; the light generation unit 12 generates signal photons 1621 and inputs them into the integrated storage unit 11; the light generation unit 12 generates control light pulses 1622 and inputs them into the integrated storage unit 11 to realize spin wave transfer; the electric generation unit 13 generates a series of radio frequency magnetic field pulses 1623 and inputs them into the integrated storage unit 11 to realize dynamic decoupling function; the light generation unit generates control light pulses 1624 and inputs them into the integrated storage unit 11 to transfer spin wave excitation into optical excitation; the polarization analyzer 14 reads out the photon polarization state 1625.

[0088] When a noiseless photon echo storage scheme is chosen, its basic idea is consistent with the atomic frequency comb scheme for spin waves. That is, when a photon is stored in a lower energy level spin state, a dynamic decoupling sequence is executed, and then it is read out as optical excitation and emitted. The specific operation steps are as follows: the light generation unit 12 generates pump light incident on the integrable storage unit 11 and prepares an isolated absorption band; the light generation unit 12 generates signal photons input to the integrable storage unit 11; the light generation unit 12 generates a series of control light pulses input to the integrable storage unit 11, realizing spin wave storage based on the noiseless photon echo storage scheme; the electrical generation unit 13 generates a series of radio frequency magnetic field pulses input to the integrable storage unit 11 to realize the dynamic decoupling function; the light generation unit 12 generates a series of control light pulses input to the integrable storage unit 11, transferring the spin wave excitation to optical excitation; the polarization analyzer 14 reads out the photon polarization state 1625.

[0089] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0090] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0091] The above is a description of a quantum storage device and method provided by the present invention. For those skilled in the art, based on the ideas of the embodiments of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A quantum storage device, characterized by, The application relates to a quantum memory device, which comprises a light generating unit, an electric generating unit, an integrable storage unit and a polarization detecting unit. The light generating unit is used for generating pump light required by the integrable storage unit, preparing polarization bit photons to be stored, and outputting the pump light and the polarization bit photons to the integrable storage unit. The electric generating unit is used for generating an electric pulse signal required by the integrable storage unit, and outputting the electric pulse signal to the integrable storage unit. The integrable storage unit is prepared on a rare earth ion doped crystal and supports transmission of arbitrary polarization states, is used for preparing a specific absorption band by using the pump light according to a specified storage scheme, and realizes on-demand reading of the polarization bit photons according to the electric pulse signal. The polarization detecting unit is used for detecting a polarization state of a photon echo generated by the stored polarization bit photons. The light generating unit comprises a laser, a first acousto-optic modulator, a second acousto-optic modulator and a polarization state preparing unit.

2. The quantum storage device of claim 1, wherein, The laser is used for generating laser light with a line width in a specified range. The first acousto-optic modulator is used for modulating the pump light required by the integrable storage unit according to the laser light, and outputting the pump light to the integrable storage unit. The second acousto-optic modulator is used for modulating signal photons to be stored according to the laser light, and outputting the signal photons to the polarization state preparing unit. The polarization state preparing unit is used for polarization bit encoding the signal photons to obtain the polarization bit photons to be stored, and outputting the polarization bit photons to the integrable storage unit. The integrable storage unit comprises an electric waveguide and an optical waveguide. The optical waveguide is used for binding the polarization bit photons.

3. The quantum storage device of claim 1, wherein, The electric waveguide is used for applying the electric pulse signal to rare earth ions located in the optical waveguide to generate a local electric pulse signal. When the specified storage scheme is an electrically controlled atomic frequency comb scheme, the specific absorption band is an absorption band with a frequency comb structure, and the electric pulse signal is a pulsed electric field signal. When the specified storage scheme is a spin wave atomic frequency comb scheme, the specific absorption band is an absorption band with a frequency comb structure, and the electric pulse signal is a radio frequency magnetic field signal. When the specified storage scheme is a noiseless photon echo scheme, the specific absorption band is an absorption band with an isolated structure, and the electric pulse signal is a radio frequency magnetic field signal.

4. The quantum storage device of claim 1, wherein, The polarization detecting unit comprises a specific wavelength wedge, a specific wavelength quarter wave plate, a specific wavelength half wave plate and a specific wavelength polarization beam splitting crystal. The specific wavelength wedge is used for compensating crystal birefringence and additional phase introduced in the storage process. The specific wavelength half wave plate and the specific wavelength quarter wave plate are used for projecting a polarization state of a photon echo generated by the stored photons to a horizontal polarization state.

5. The quantum storage device of claim 1, wherein, The polarization beam splitting crystal is used for polarization detection, filters a horizontal polarization component in the echo photons, and finally enters a single photon detector for detection. ​ ​ ​ ​ 6. The quantum storage device of claim 1, wherein, The optical transition of the rare-earth ion doped crystal has consistent absorption depth for two orthogonal polarization components.

7. The quantum memory device of claim 3, wherein, The performance of the optical waveguide is polarization independent, supporting transmission of arbitrary polarization states.

8. The quantum memory device of claim 3 or 7, wherein, The optical waveguide is disposed within a range of 20 microns from the surface of the rare-earth ion doped crystal. The electrical waveguide is disposed on the surface of the rare-earth ion doped crystal.

9. The quantum storage device of claim 1, wherein, The rare earth ion doped crystal is a Eu:YSO crystal, and the Eu ions on the site 2 in the Eu:YSO crystal 7 F0- 5 The D0 energy level transition satisfies the condition that two orthogonal polarization components have consistent absorption depth.

10. A storage method of a quantum storage device, characterized by, The storage device comprises a light generating unit, an electrical generating unit, an integrable storage unit and a polarization detecting unit, the integrable storage unit is prepared on a rare-earth ion doped crystal, and the method comprises: The light generating unit is used to generate pump light required by the integrable storage unit, and prepare polarization bit photons to be stored, and output the pump light and the polarization bit photons to the integrable storage unit; The electrical generating unit is used to generate electrical pulse signals required by the integrable storage unit, and output the electrical pulse signals to the integrable storage unit; The integrable storage unit is used to prepare a specific absorption band according to the pump light and realize on-demand reading of the polarization bit photons according to the electrical pulse signals according to a specified storage scheme; The polarization detecting unit is used to detect the polarization state of a photon echo generated by the stored polarization bit photons.

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