DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102 of this title, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-11 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Curchod et al (WO 2002/053812; art cited by applicant) in view of Kuzmich et al (US 2008/0252049; art cited by applicant).
Regarding independent claim 1, Curchod teaches a method comprising: obtaining a first quantum state (Fig. 15 and page 91, 1st paragraph: individual quantum states representing the states corresponding to pump photo transmission through a first optical path); obtaining a second quantum state (Fig. 15a and page 91, 1st paragraph: individual quantum states representing the states corresponding to pump photon transmission through a second optical path); providing the first quantum state to a first single-photon addition module (Fig. 15 and page 91, 1st paragraph: pump photons exiting the photon source 1504 may be divided into a first and second pump photon streams; the first pump photon stream is transmitted to a first photon generator 1506), wherein the first single-photon addition module generates as output a first idler state and a first photon addition signal state (Fig. 15 and page 91, 2nd paragraph: each photon pair generator 1506/1508 may generate a pair of photons upon receiving two or more pump photons; a first photon is referred to as a signal photon and a second photon is referred to as an idler photon); providing the second quantum state to a second single-photon addition module (Fig. 15a and page 91, 1st paragraph: pump photons exiting the photon source 1504 may be divided into a first and second pump photon streams; the second pump photon stream is transmitted to a second photon pair generator 1508), wherein the second single-photon addition module generates as output a second idler state and a second photon addition signal state (Fig. 15 and page 91, 2nd paragraph: each photon pair generator 1506/1508 may generate a pair of photons upon receiving two or more pump photons; a first photon is referred to as a signal photon and a second photon is referred to as an idler photon). Curchod fails to explicitly disclose mixing, using a beam splitter associated with a pair of outputs respectively connected to upper and lower branch single photon detectors (SPDs), an input including: a first idler photon associated with the first idler state generated by the first single-photon addition module; and a second idler photon associated with the second idler state generated by the second single-photon addition module. However, Kuzmich, from the same field of endeavor, teaches generating an entangled pair of photons (Abstract) to include mixing, using a beam splitter associated with a pair of outputs respectively connected to upper and lower branch single photon detectors (SPDs) (Fig. 7 and [0067], the two outputs of the fiber beam splitter may be connected to detectors D2 and D3; electronic pulses from the detectors may be gated with time windows centered on times determined by the write and read lights pulses of detectors D1, D2, and D3) an input including: a first idler photon associated with the first idler state generated by the first single-photon addition module; and a second idler photon associated with the second idler state generated by the second single-photon addition module (Fig 7 and [0067], the idler field polarization orthogonal to that of the read beam may be directed into a single-mode fiber beam splitter; both write-read and signal-idler pairs of fields may be counterpropagating). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Curchod by employing the teachings as taught by Kuzmich so as to allow idler fields to be fed to single-photon detectors (Kuzmich: Fig. 7 and [0067]), thereby allowing the quality of single protons produced to be assessed using photoelectric detection probabilities measured by a set of detectors (Kuzmich: Fig. 7 and [0071]).
Regarding dependent claim 2, Curchod as modified by Kuzmich further teaches detecting a photon on either the upper branch SPD or the lower branch SPD (Curchod: Fig. 15 and page 93, para 2, the entangled photons generated by the quantum state generator 1510 may be provided to a measurement stage 1512 where their quantum state is measured; the measurement stage 1512 may comprise two identical measuring devices 1514/1516, each comprising a plurality of optical paths, each optical path ending in a photon detector); wherein the first quantum state and the second quantum state are entangled based on an uncertainty associated with the detected photon being associated with either the first idler state or the second idler state (Curchod: Fig. 15 and page 93, the signal photons of the photon pairs generated by the photon generators 1506/1508 may be transmitted through a first output 1511a and the idler photons of the photon pairs generated by the photon generators 1506/1508 may be transmitted through a second output 1511b; the photons received from these two outputs may be entangled photons; the first output1 provides a first qubit and the second output 1511b provides a second qubit; the collective quantum state of the photons output from the first 1511a and second 1511b outputs of the quantum state generator 1510 may be expressed where lab> is the quantum state of the signal and idler photons generated by the first photon pair generator 1506, la'b'> is the quantum state of the signal and idler photons generated by the second photon pair generator 1508. a and ß are the superposition weight coefficients).
Regarding dependent claim 3, Curchod as modified by Kuzmich further teaches wherein: the first quantum state and the second quantum state include one or more of a discrete-variable (DV) quantum state, a continuous-variable (CV) quantum state, a hybrid CV-DV entangled quantum state, or a macroscopic quantum state (Curchod: Fig. 29 and page 25, para. 4, the quantum computer 3200 may be configured in some implementations to perform four sets of local measurements on Greenberger-Horne-Zeilinger states of three qubits; the measurement settings can change round-on-round, or can be fixed for a quarter of the total number of rounds each; a Greenberger-Horne-Zeilinger state is a certain type of entangled quantum state that involves at least three subsystems, for example particle states or qubits).
Regarding dependent claim 4, Curchod as modified by Kuzmich further teaches wherein the first quantum state is independent from the second quantum state (Curchod: Fig. 15 and page 95, para. 2, different pairs of detectors may measure the quantum states of the photons in different bases).
Regarding dependent claim 5, Curchod as modified by Kuzmich further teaches wherein the first and second single photon-addition modules, except the upper and lower branch SPDs and a pump diode, are integrated on a same chip (Curchod: Fig. 18 and page 105, para. 3, a PPG can be a two-port device with one input port and one output port, wherein the frequency of the photons exiting the output port may be different from the frequency of the photons entering the input port; the photons exiting the output port may be generated by the photons entering the input port via a nonlinear optical phenomenon within the PPG; two photons having the same frequencies may enter the input port and two photons with different frequencies that are also different from the frequency of the photons entering the PPG may exit the output port; a PPG can have a plurality of input ports and output ports, wherein the photons exiting one or more output ports may have a frequency different from the frequency of the photons entering one or more input ports; in a preferred embodiment, a PPG can be an on-chip device attached to or fabricated on a substrate formed from one or more materials).
Regarding dependent claim 6, Curchod as modified by Kuzmich further teaches wherein the first quantum state is a first multipartite state and the second quantum state is a second multipartite quantum state (Curchod: Fig. 29 and page 25, para. 2, the quantum computer 3200 may be configured in some implementations to perform four sets of local measurements on Greenberger-Horne-Zeilinger states of three qubits; the measurement settings can change round-on-round, or can be fixed for a quarter of the total number of rounds each; a Greenberger-Horne-Zeilinger state is a certain type of entangled quantum state that involves at least three subsystems, for example particle states or qubits).
Regarding dependent claim 7, Curchod as modified by Kuzmich further teaches wherein providing the first multipartite state to the first single-photon addition module comprises: providing a last qubit of the first multipartite state to the first single-photon addition module (Curchod: Fig. 15 and page 90, para. 3, the quantum apparatus 1502 comprises a quantum state generator 1510 which generates and prepares entangled photons serving as entangled qubits and a measurement stage 1512 that measures the qubits generated by the quantum state generator 1510).
Regarding dependent claim 8, Curchod as modified by Kuzmich further teaches wherein providing the second multipartite state to the second single-photon addition module comprises: providing a first qubit of the second multipartite state to the second single-photon addition module (Curchod: Fig. 15 and page 90, para. 3, the quantum apparatus 1502 comprises a quantum state generator 1510 which generates and prepares entangled photons serving as entangled qubits and a measurement stage 1512 that measures the qubits generated by the quantum state generator 1510; and Fig. 15 and page 91, para. 1, the stream of pump photons exiting the photon source 1504 may be divided into a first and a second pump photon streams; the first pump photon stream is transmitted to a first photon generator 1506 and the second pump photon stream is transmitted to a second photon pair generator 1508).
Regarding dependent claim 9, Curchod as modified by Kuzmich further teaches entangling the first multipartite state and the second multipartite state by interacting the first and second idler photons on the beam splitter, wherein detection of a photon on either the upper branch SPD or the lower branch SPD indicates that the multipartite states are entangled. Kuzmich teaches generating an entangled pair of photons (Abstract)to include entangling the first multipartite state and the second multipartite state by interacting the first and second idler photons on the beam splitter (Kuzmich: Fig 7 and [0067], the idler field polarization orthogonal to that of the read beam may be directed into a single-mode fiber beam splitter; both write-read and signal-idler pairs of fields may be counterpropagating), wherein detection of a photon on either the upper branch SPD or the lower branch SPD indicates that the multipartite states are entangled (Kuzmich: Fig. 6 and [0059], two-photon interference and photoelectric detection of signal photons produced by two remote single-atom nodes may result in entanglement of these remote atomic qubits).
Regarding dependent claim 10, Curchod as modified by Kuzmich further teaches performing entanglement swapping between a first entangled pair and a second entangled pair, wherein the first quantum state is included in the first entangled pair and the second quantum state is included in the second entangled pair. Kuzmich teaches generating an entangled pair of photons (Abstract) to include performing entanglement swapping between a first entangled pair and a second entangled pair, wherein the first quantum state is included in the first entangled pair and the second quantum state is included in the second entangled pair (Kuzmich: Fig. 6 and [0059], cascaded entanglement swapping between successive pairs of remote entangled atomic qubits may be achieved via local coupling of one of the atoms from the first pair and its neighboring partner from the following pair).
Regarding dependent claim 11, Curchod as modified by Kuzmich further teaches entangling an additional quantum state included in the first entangled pair with an additional quantum state included in the second entangled pair, based on interacting the first and second idler photons on the beam splitter, wherein detection of a photon on either the upper branch SPD or the lower branch SPD indicates that the first entangled pair is entangled with the second entangled pair. Kuzmich teaches generating an entangled pair of photons (Abstract) to include entangling an additional quantum state included in the first entangled pair with an additional quantum state included in the second entangled pair (Kuzmich: Fig. 6 and [0059], cascaded entanglement swapping between successive pairs of remote entangled atomic qubits may be achieved via local coupling of one of the atoms from the first pair and its neighboring partner from the following pair), based on interacting the first and second idler photons on the beam splitter (Kuzmich: Fig 7 and [0067], the idler field polarization orthogonal to that of the read beam may be directed into a single-mode fiber beam splitter; both write-read and signal-idler pairs of fields may be counterpropagating), wherein detection of a photon on either the upper branch SPD or the lower branch SPD indicates that the first entangled pair is entangled with the second entangled pair (Kuzmich: Fig. 6 and [0059], two-photon interference and photoelectric detection of signal photons produced by two remote single-atom nodes may result in entanglement of these remote atomic qubits).
Regarding dependent claim 13, Curchod as modified by Kuzmich further teaches wherein the first quantum state and the second quantum state both comprise macroscopic continuous variable (CV) light states and are mixed using the beam splitter to generate an entangled CV-CV macroscopic state. Kuzmich teaches generating an entangled pair of photons (Abstract), wherein the first quantum state and the second quantum state both comprise macroscopic continuous variable (CV) light states
and are mixed using the beam splitter to generate an entangled CV-CV macroscopic state (Kuzmich: Fig 7 and [0067], the idler field polarization orthogonal to that of the read beam may be directed into a single-mode fiber beam splitter; both write-read and signal-idler pairs of fields may be counterpropagating; the two outputs of the fiber beam splitter may be connected to detectors D2 and D3; electronic pulses from the detectors may be gated with windows centered on times determined by the write and read light pulses; subsequently, the electronic pulses from D1, D2, and D3 may be fed into a time-interval analyzer which records photoelectric detection events; and Fig. 6 and [0059],
two-photon interference and photoelectric detection of signal photons produced by two remote single-atom nodes may result in entanglement of these remote atomic qubits).
Claims 14, 19 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Curchod et al (WO 2002/053812; art cited by applicant) in view of Kuzmich et al (US 2008/0252049; art cited by applicant) and further in view of Xian Institute of Space Radio Technology (“Xian”) (CN 110658634; art cited by applicant. An English machine translation is used herewith).
Regarding dependent claim 14, Curchod as modified by Kuzmich fails to further teach applying a phase shift to either the beam splitter input of the first idler photon or the beam splitter input of the second idler photon; wherein the phase shift is selected such that the output macroscopic CV states are entangled. However, Xian, from the same field of endeavor, teaches a processing system and method for mixed entanglement of continuous variable polarization and orbital angular momentum (Abstract) to include applying a phase shift to either the beam splitter input of the first idler photon or the beam splitter input of the second idler photon; wherein the phase shift is selected such that the output macroscopic CV states are entangled (Xian: Fig. 2 and page 9, para 3, the orbital angular momentum measurement sub-unit 42 may specifically include: an alternating current and direct current detector 424, an alternating current and direct current detector 425 and a subtracter 426; the output end of the subtracter 426 outputs a current difference signal by adjusting the angles of pi mode phase shifter 421 and 422, and the noise fluctuation of the orbit Stokes parameter is measured; and page 8, para 12, the stokes parameter measuring unit 4 measures and verifies the quantum noise of the polarization stokes parameter of the light beam iii 23 output by the horizontal output end of the polarization beam splitter 22). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Curchod as modified by Kuzmich by using the phase shifter features of Xian so as to allow current difference signals to be output by adjusting the angles of pi mode phase shifters (Xian: page 8, para 12), thereby allowing a combined measurement of polarization-orbit degree of freedom hybrid entanglement (Xian: page 8, para 12).
Regarding dependent claim 19, Curchod as modified by Kuzmich further teaches
a Quantum Key Distribution (QKD) network (Curchod: fig. 28 and page12, para. 3, the cryptographic system further includes a key distribution apparatus 3060 that is configured in use to receive the encryption keys 3050 from the key generation apparatus 3040 and to encrypt the one or more received encryption keys 3050 to generate one or more corresponding encrypted encryption keys 3070 and to distribute the one or more corresponding encrypted encryption keys 3070 to the one or more users 3010; and fig. 28 and page 16, para. 3, the system 3000 is configured to use the following protocol which is well-suited for use in generating the quantum-grade encryption keys 3050). Curchod as modified by Kuzmich fails to explicitly teach implementing a hybrid continuous variable-discrete variable (CV-DV) network based on one or more entangled hybrid quantum states, wherein the one or more entangled hybrid quantum states are entangled based on mixing, using a beam splitter, a pair of idler photons output by a respective pair of single-photon addition modules each
associated with an input quantum state of an entangled hybrid quantum state pair. However, Xian, from the same field of endeavor, teaches a processing system and method for mixed entanglement of continuous variable polarization and orbital angular momentum (Abstract) to include implementing a hybrid continuous variable-discrete variable (CV-DV) network based on one or more entangled hybrid quantum states, wherein the one or more entangled hybrid quantum states are entangled based on mixing (Xian: Fig. 2 and page 8, para. 7, the stokes parameter measuring unit 4 is used for measuring and verifying the light beam III 23 and the light beam IV 33 which are mixed and entangled by continuous variable polarization and orbital angular momentum), using a beam splitter (Xian: page 8, para. 12, the polarization quantum unit 41 under the stokes parameter measuring unit 4 measures and verifies the quantum noise of the polarization stokes parameter of the light beam iii 23 output by the horizontal output end of the polarization beam splitter 22), a pair of idler photons output by a respective pair of single-photon addition modules each associated with an input quantum state of an entangled hybrid quantum state pair (Xian: page 9, para. 5, the current difference signals output by the subtracter I416 and the subtracter II 426 are subjected to addition and subtraction operations on the adder-subtractor 43, SO that the combined measurement of polarization-orbit degree of freedom hybrid entanglement is realized). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Curchod as modified by Kuzmich by employing the teaching of the entangled hybrid quantum state features of Xian so as to allow a combined measurement of polarization-orbit degree of freedom hybrid entanglement, thereby allowing generation and verification of the mixed entanglement of the continuous variable polarization-orbital angular momentum.
Regarding dependent claim 20, Curchod as modified by Kuzmich further teach performing QKD (Curchod: fig. 28 and page 12, para. 3, the cryptographic system further includes a key distribution apparatus 3060 that is configured in use to receive the encryption keys 3050 from the key generation apparatus 3040 and to encrypt the one or more received encryption keys 3050 to generate one or more corresponding encrypted encryption keys 3070 and to distribute the one or more corresponding encrypted
encryption keys 3070 to the one or more users 3010; and fig. 28 and page 16, para. 3, the system 3000 is configured to use the following protocol which is well-suited for use in generating the quantum-grade encryption keys 3050). Curchod as modified by Kuzmich fails to explicitly teach generating an entangled DV-DV quantum state pair using a first beam splitter with inputs coupled to the respective outputs of a pair of single-photon addition modules; generating an entangled CV-CV quantum state pair using a second beam splitter with inputs coupled to the respective outputs of a second pair of single- photon addition modules; entangling the entangled DV-DV quantum state pair with the entangled CV- CV quantum state pair using a third beam splitter with inputs configured to receive a DV quantum state of the entangled DV-DV quantum
state pair and a CV quantum state of the entangled CV-CV quantum state pair; and performing hybrid CV-DV based on first and second entangled CV-DV pairs generated from the entangled DV-DV quantum state pair and entangled CV-CV quantum state pair. However, Xian, from the same field of endeavor, teaches a processing system and method for mixed entanglement of continuous variable polarization and orbital angular momentum (Abstract), comprising generating an entangled DV-DV quantum state pair using a first beam splitter with inputs coupled to the respective outputs of a pair of single-photon addition modules (Xian: page 8, para. 10, the polarization entanglement unit 2 may be specifically configured to receive an EPR entangled light beam I11 input through an input end I of a polarization entanglement unit 2 and receive the vertically
polarized HG01 mode laser light 21 input through the input terminal ii of the polarization entanglement unit 2, through polarization beam splitter 22 under polarization entanglement unit 2; the polarization quantum unit 41 under the stokes parameter measuring unit 4 measures and verifies the quantum noise of the polarization stokes parameter of the light beam iii 23 output by the horizontal output end of the polarization beam splitter 22); generating an entangled CV-CV quantum state pair using a second beam splitter with inputs coupled to the respective outputs of a second pair of single-
photon addition modules (Xian: page 9, para. 1, the orbital angular momentum entanglement unit 3 may be specifically configured to receive an EPR entangled light beam II 12 input through an input end I of the orbital angular momentum entanglement unit 3 and receiving the horizontally polarized HG10 mode laser 31 input through the input end II of the orbital angular momentum entanglement unit 3, through mode coupler 32 under the orbital angular momentum entanglement unit 3); entangling the entangled DV-DV quantum state pair with the entangled CV- CV quantum state pair using a third beam splitter with inputs configured to receive a DV quantum state of the entangled DV-DV quantum state pair and a CV quantum state of the entangled CV-CV quantum state pair; and performing hybrid CV-DV based on first and second entangled CV-DV pairs generated from the entangled DV-DV quantum state pair and entangled CV-CV
quantum state pair (Xian: page 9, para. 5, the stokes parameter measuring unit 4 may further include an adder-subtractor 43; the current difference signals output by the subtracter I416 and the subtracter II 426 are subjected to addition and subtraction operations on the adder-subtractor 43, so that the combined measurement of polarization-orbit degree of freedom hybrid entanglement is realized). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Curchod as modified by Kuzmich by employing the teaching of the entangled hybrid quantum state features of Xian so as to allow a combined measurement of polarization-orbit degree of freedom hybrid entanglement, thereby allowing generation and verification of the mixed entanglement of the continuous variable polarization-orbital angular momentum.
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Curchod et al (WO 2002/053812; art cited by applicant) in view of Kuzmich et al (US 2008/0252049; art cited by applicant) and further in view of Zavatta et al. (Document entitled: “A high-fidelity noiseless amplifier for quantum light states”; art cited by applicant).
Regarding dependent claim 15, Curchod as modified by Kuzmich fails to further teach performing noiseless amplification by providing an arbitrary state as input to a photon amplifier, wherein: the photon amplifier includes a photon addition stage coupled to a photon subtraction stage, wherein an output of the photon addition stage is coupled to an input of the photon subtraction stage; and the input state to the photon amplifier is provided in a superposition state that causes the photon amplifier to apply a noise-free gain. However, Zavatta, in the same field of endeavor, teaches a noiseless linear amplifier (Zavatta: Abstract) comprising performing noiseless amplification by providing an arbitrary state as input to a photon amplifier (Zavatta: page 1, para. 3, quantum information is encoded in the complex amplitude α of a coherent state la>; and page 2, fig. 2, two blocks for conditional single-photon addition and subtraction are placed in the path of a coherent state), wherein: the photon amplifier includes a photon addition stage coupled to a photon subtraction stage, wherein an output of the photon addition stage is coupled to an input of the photon subtraction stage (Zavatta: page 2, fig. 2, two blocks for conditional single-photon addition and subtraction are placed in the path of a coherent state); and the input state to the photon amplifier is provided in a superposition state (Zavatta: page 2, para. 1, addition and subtraction of single photons are the result of the application of the creation and annihilation operators to an arbitrary state of light; depending on the ordering of such operations, a transformation can be applied to the initial state; sequences and coherent superpositions of such quantum operators have been recently demonstrated) that causes the photon amplifier to apply a noise-free gain (Zavatta: page 2, para. 2, application of such transformation results in noiseless amplification). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Curchod as modified by Kuzmich by employing the teaching of the noiseless amplifier features of Zavatta so as to allow two blocks of conditional single-photon addition and subtraction to be placed in the path of a coherent state (Zavatta: page 2, fig. 2), thereby allowing the amplification of coherent states at the highest level of effective gain and final state fidelity (Zavatta: Abstract).
Claims 16 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Curchod et al (WO 2002/053812; art cited by applicant) in view of Kuzmich et al (US 2008/0252049; art cited by applicant) and further in view of Ashikhmin (US 2014/0365843; art cited by applicant).
Regarding dependent claim 16, Curchod as modified by Kuzmich fails to further teach obtaining, at a first node of a Quantum Communication Network (QCN), an input quantum information state comprising one or more qubits; generating, by the first QCN node, a quantum low-density parity-check (QLDPC) codeword based on the input quantum information state, wherein the first QCN node generates the QLDPC codeword by encoding the input quantum information state using a QLDPC code; and transmitting the QLDPC codeword from the first QCN node to an intermediate QCN node, wherein the first QCN node and the intermediate QCN node are included in a Quantum Error Correction (QEC)-based QCN. However, Ashikhmin, from the same field of endeavor, teaches error detection using a redundant measurement based on a block error-
correction code (Abstract) comprising obtaining, at a first node of a Quantum
Communication Network (QCN), an input quantum information state comprising one or more qubits (Ashikhmin: fig. 1 and [0039], QSR module 130 is configured to serially process different entangled quantum states stored in a qubit array 110); generating, by the first QCN node, a quantum low-density parity-check (QLDPC) codeword based on the input quantum information state, wherein the first QCN node generates the QLDPC
codeword by encoding the input quantum information state using a QLDPC code (Ashikhmin: fig. 1 and [0036], each entangled qubit state stored in qubit array 110 is encoded using a quantum stabilizer code; fig. 1 and [0036], one representation of the quantum stabilizer code Q is a group of G; and fig. 1 and [0038], group G represents a quantum LPDC code); and transmitting the QLDPC codeword from the first QCN node to an intermediate QCN node, wherein the first QCN node and the intermediate QCN node are included in a Quantum Error Correction (QEC)-based QCN (Ashikhmin: fig. 1 and [0041], QSR module 130 comprises a qubit buffer 134, an error-detection circuit 138, and a quantum-state recovery circuit 148; qubit buffer 134 comprises one or more qubit registers configured to hold the received qubits for the duration of the corresponding error-correction processing; error-detection circuit 138 is configured to implement the above-specified step (i) of the error-correction processing; quantum-state recovery circuit 148 is configured to act on the entangled quantum state in qubit buffer 134 to implement the above-specified step (ii) of the error-correction processing). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Curchod as modified by Kuzmich by employing the teaching of the codeword features of Ashikhmin so as to allow detection of an error using a redundant measurement based on a block
error-correction code, thereby allowing an entangled qubit state in a qubit array to be changed when an error is detected (Ashikhmin: Abstract).
Regarding dependent claim 17, Curchod as modified by Kuzmich fails to further teach receiving, at the intermediate QCN node, the QLDPC codeword transmitted from the first QCN node; correcting, at the intermediate QCN node, a most probable quantum error operator identified by the intermediate QCN node; and re-encoding, at the intermediate QCN node, the error-corrected QLDPC codeword, wherein the intermediate QCN node inserts one or more additional redundant qubits in the re-encoded QLDPC codeword; wherein soft-decision decoding is performed at a final QCN node of the QCN. However, Ashikhmin, from the same field of endeavor, teaches error detection using a redundant measurement based on a block error-correction code (Abstract), comprising receiving, at the intermediate QCN node, the QLDPC codeword transmitted from the first QCN node (Fig. 1 and [0041], qubit buffer 134 comprises one or more qubit registers configured to hold the received qubits for the duration of the corresponding error-correction processing); correcting, at the intermediate QCN node, a most probable quantum error operator identified by the intermediate QCN node (Fig. 1 and [0040-0041], error-detection circuit 138 is configured to determine whether or not the received set of qubits corresponding to an entangled quantum state has an error; quantum-state recovery circuit 148 is configured to act on the entangled quantum state in qubit buffer 134 and if an error is detected, then changing the qubit state to correct the detected error); and re-encoding, at the intermediate QCN node, the error-corrected QLDPC codeword, wherein the intermediate QCN node inserts one or more additional redundant qubits in the re-encoded QLDPC codeword (Fig. 1 and [0042], error-detection circuit 138 includes a syndrome-measurement circuit 140 and a decoder 144 coupled to each other and to other circuits in QSR module 130; Fig. 1 and [0043], syndrome-measurement circuit 140 is a quantum circuit configured to perform a redundant measurement, on the encoded entangled quantum state in qubit buffer 134, of a set of syndrome values; Fig. 1 and [0043], syndrome-measurement circuit 140 includes quantum circuitry that causes the generated binary vector y to be a codeword of the block error-correction code C when all of binary values are measured accurately; and Fig. 1 and [0044], if the vector V generated by syndrome-measurement circuit 140 is determined to not be a valid codeword of block error-correction code C, then the binary values s1 are processed as not having been measured accurately); wherein soft-decision decoding is performed at a final QCN node of the QCN (Fig. 1 and [0044], decoder 144 is configured to process the measured vector V in accordance with the block error-correction code C to determine the most probable valid codeword corresponding to the measured vector v). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Curchod as modified by Kuzmich by employing the teaching of the codeword features of Ashikhmin so as to allow detection of an error using a redundant measurement based on a block error-correction code, thereby allowing an entangled qubit state in a qubit array to be changed when an error is detected (Ashikhmin: Abstract).
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Curchod et al (WO 2002/053812; art cited by applicant) in view of Kuzmich et al (US 2008/0252049; art cited by applicant) and further in view of Pfister et al (US 2023/0341744).
Regarding dependent claim 18, Curchod as modified by Kuzmich fails to further teach wherein: the first and second quantum states are both obtained cluster states associated with nodes of a Quantum Communication Network (QCN), wherein the QCN includes a plurality of nodes arranged in a 2D cluster state; and the plurality of nodes arranged in the 2D cluster state of the QCN are entangled based on performing delocalized photon addition between one or more pairs of nodes. However, Pfister, in the same field of endeavor, teaches systems and methods for generating cluster quantum states (Abstract) the first and second quantum states are both obtained cluster states associated with nodes of a Quantum Communication Network (QCN), wherein the QCN includes a plurality of nodes arranged in a 2D cluster state (Fig. 4A and [0088], the number macronodes, the number of spokes, and the number of macronodes along each spoke in a 2D graph associated with a 2D cluster state can be controlled by the number and a relative magnitude of modulation frequencies used to generate the 2D cluster state); and the plurality of nodes arranged in the 2D cluster state of the QCN
are entangled based on performing delocalized photon addition between one or more pairs of nodes ([0100], the plurality of qumodes may comprise a plurality of entangled qumode pairs in two-mode qumode entangled states where each two-qumode entangled state comprises a first qumode having a frequency wd,m = wp/2-(M+1/2)xFSR and a second qumode having a frequency ou,m = wp/2+ (M+1/2)xFSR where M is an integer). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Curchod as modified by Kuzmich by employing the teaching of the cluster features of Pfister so as to allow generation of a cluster quantum state using a single source of independent entangled quantum states (Pfister: [0013]), thereby allowing large and complex CV cluster states to be generated and controlled for universal quantum computation (Pfister: [0014]).
Allowable Subject Matter
Claim 12 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Conclusion
Examiner's note: Examiner has cited particular columns and line numbers in the references as applied to the claims above for the convenience of the applicant. Although the specified citations are representative of the teachings of the art and are applied to the specific limitations within the individual claim, other passages and figures may apply as well. It is respectfully requested from the applicant, in preparing responses, to fully consider the references in entirety as potentially teaching all or part of the claimed invention, as well as the context of the passage as taught by the prior art or disclosed by the Examiner.
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. References Kuzmich et al (US 2006/0163465), Pittman et al (US 2006/0164706), Lukim et al (US 2011/0222848), Barlett et al (US 2023/0376817), Vacon et al (US 2024/0405886) and MacQuarrie et al (US 2025/0233673) are cited because they are pertinent to the method and apparatus for quantum communications. However, none of the cited references teaches or suggests the further arrangements as recited in the dependent claim 12.
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/DON N VO/Primary Examiner, Art Unit 2634
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