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 .
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Response to Amendment
Claims 1-19 are pending. Claims 1 and 15 stand amended.
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 1-10 and 15-19 are rejected under 35 U.S.C. 103 as being unpatentable over Doherty (US 20240303522 A1) in view of Rudolph (US 20260161987 A1).
Regarding claim 1, 2, Doherty teaches an apparatus (e.g. Fig. 9A) comprising:
an optical circuit (id., a photonic circuit) comprising:
an interferometer (¶31, “Fig. 9A shows a circuit diagram for a dual-rail-encoded type II fusion gate that can be used in some embodiments.”) arranged to:
receive, as 2N input optical modes, a plurality of N dual-rail encoded photonic qubits (Qubit A and Qubit B), each dual-rail encoded photonic qubit encoded in a single-photon dual-rail basis defined by a respective pair of orthogonal optical modes (¶2, “At the most general level, a qubit is a quantum system that can exist in one of two orthogonal states (denoted as |0> and |1> in the conventional bra-ket notation”; ¶86, “In a dual-rail encoding, each pair of modes represents a qubit. In a photonic implementation of the gate the modes in diagrams such as that shown in FIG. 9A can be physically realized using single photons in photonic waveguides.”);
interfere the N dual-rail encoded photonic qubits via beamsplitter interactions (¶91, “Thus, type II fusion gate 900 takes as input two dual-rail-encoded photon qubits thereby resulting in a total of four input modes (e.g., modes 943, 945, 947, and 949). To accomplish the fusion operation, a first mode coupler (e.g., 50/50 beam splitter) 953 is applied between a mode of each of the input qubits, e.g., between mode 943 and mode 949, and a second mode coupler (e.g., 50/50 beam splitter) 955 is applied between the other modes of each of the input qubits, e.g., between modes 945 and 947.”), the beamsplitter interactions comprising:
a beamsplitter interaction (953) on the first mode of the first qubit and the second mode of the Nth qubit (id.); and
a beamsplitter interaction (955) on the second mode of the jth qubit and the first mode of the (j+1)th qubit for all j between 1 and N - 1, wherein j is an integer; and
output 2N optical modes (¶91, “A detection operation is performed on all four [output] modes …”); and
a detector arrangement comprising one or more photodetectors, the detector arrangement configured to measure a photon occupation of each of the 2N output optical modes (¶91, “A detection … using photon detectors 957(1)-957(4).”, and ¶82, number of photons measured).
Doherty explicitly contemplates N>2 qubit entangled states (¶63, “3-GHZ” state mathematical form).
Doherty does not explicitly show the apparatus wherein single photon dual rail encoding qubits where N is an integer greater than two.
Rudolph, drawn to dual-rail quantum computing devices, explicitly details the required apparatus for achieving Doherty’s 3-GHZ state, i.e. an N>2 entangled state (¶27, ¶114-115, Fig. 18, detailing the 3-GHZ state generator having N>2 single photon sources and mode couplers among several mode pairs to generate the encodings; cf. Applicant’s Fig. 1A with Rudolph’s Fig. 18, 1822).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have utilized the apparatus of Rudolph to achieve the 3-GHZ dual rail encoding qubit state known to Doherty and thus predictably increased the logical capability of the quantum computation.
Regarding claim 3, the modified Doherty teaches the apparatus according to claim 1, and further discloses wherein the detector arrangement comprises one or more photon number resolving photodetectors (¶82).
Regarding claim 4, the modified Doherty teaches the apparatus according to claim 1, and further discloses wherein the detector arrangement comprises one or more threshold photodetectors (it is considered that any detector can be considered to be responsive to a threshold, e.g. to a minimum number of photons, such as an output mode of Doherty in Fig. 9A).
Regarding claim 5, the modified Doherty teaches the apparatus according to claim 1, further comprising a second optical circuit configured to dual-rail encode the photonic qubits as 2N input optical modes (¶68-70, Figs. 2A, 2B).
Regarding claim 6, the modified Doherty teaches the apparatus according to claim 1, and further discloses wherein the input optical modes and output optical modes are spatial modes (¶56-57).
Regarding claim 7, the modified Doherty teaches the apparatus according to claim 6, and further discloses wherein the interferometer is a spatial interferometer including 2N input ports for inputting the N dual-rail encoded qubits to the interferometer and further including 2N output ports for outputting the 2N output optical modes towards the detector arrangement (Fig. 9A, ¶89).
Regarding claim 8, the modified Doherty teaches the apparatus according to claim 7, and further discloses wherein the spatial interferometer (Fig. 9A, ¶89) comprises a plurality of waveguides arranged to pass through the interferometer to connect the 2N input ports to the 2N output ports; wherein the plurality of waveguides are arranged to provide coupling locations between pairs of the plurality of waveguides, wherein a waveguide coupler is arranged at each of at least a subset of the coupling locations such that at each of those coupling locations the two optical modes carried by the two respective waveguides are capable of coupling with each other in a beamsplitter interaction (Fig. 9A, ¶89).
Regarding claim 9 and 10, the modified Doherty teaches the apparatus according to claim 1, and further discloses wherein at least the interferometer is provided on a photonic integrated circuit (¶64, “qubits are provided in an integrated photonic system employing waveguides, beam splitters, photonic switches, and single photon detectors, and the modes that can be occupied by photons are spatiotemporal modes that correspond to presence of a photon in a waveguide”).
Regarding claim 15, Doherty teaches a method for entangling a plurality of N photonic multiqubit states (¶63, “an n-qubit Greenberger-Horne-Zeilinger (GHZ) state (or “n-GHZ state”) is an entangled quantum state of n qubits. For a given orthonormal logical basis, an n-GHZ state is a quantum superposition of all qubits being in a first basis state superposed with all qubits being in a second basis state”), the method comprising performing a N-qubit state measurement on a set of photonic qubits (¶64), the set comprising one photonic qubit from each of the N photonic multiqubit states (Fig. 9A, Qubit A and/or Qubit B by the detectors 957), wherein performing the N-qubit state measurement comprises:
dual-rail encoding each photonic qubit of the set in a single-photon dual-rail basis defined by a respective pair of orthogonal optical modes (Fig. 9A, ¶91, “Thus, type II fusion gate 900 takes as input two dual-rail-encoded photon qubits thereby resulting in a total of four input modes (e.g., modes 943, 945, 947, and 949). To accomplish the fusion operation, a first mode coupler (e.g., 50/50 beam splitter) 953 is applied between a mode of each of the input qubits, e.g., between mode 943 and mode 949, and a second mode coupler (e.g., 50/50 beam splitter) 955 is applied between the other modes of each of the input qubits, e.g., between modes 945 and 947.”);
providing the dual-rail encoded photonic qubits to an interferometer (Fig. 9A, interfered at 953, 955), the interferometer configured to:
perform a beamsplitter interaction (at 953 and 955) on the first mode of the first qubit and the second mode of the Nth qubit (¶91); and
perform a beamsplitter interaction on the second mode of the jth qubit and the first mode of the (j + 1)th qubit for all j between 1 and N - 1, wherein j is an integer (Fig. 9A, ¶91); and
measuring a photon occupation of optical modes output from the interferometer (¶68, “Any type of photodetector that has sensitivity to single photons can be used. In some embodiments, detection of a photon (e.g., at the output end of a waveguide) indicates an occupied mode while absence of a detected photon can indicate an unoccupied mode.”).
Doherty explicitly contemplates N>2 qubit entangled states (¶63, “3-GHZ” state mathematical form).
Doherty does not explicitly show the required steps for wherein single photon dual rail encoding qubits where N is an integer greater than two.
Rudolph, drawn to dual-rail quantum computing devices, explicitly details the required steps for achieving Doherty’s 3-GHZ state, i.e. an N>2 entangled state (¶27, ¶114-115, Fig. 18, detailing the 3-GHZ state generator having N>2 single photon sources and mode couplers among several mode pairs to generate the encodings; cf. Applicant’s Fig. 1A with Rudolph’s Fig. 18, 1822).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have utilized the steps of Rudolph to achieve the 3-GHZ dual rail encoding qubit state known to Doherty and thus predictably increased the logical capability of the quantum computation.
Regarding claim 16, the modified Doherty teaches the method according to claim 15, and further discloses further comprising, based on the measured photon occupation of the output modes, performing corrective operations on at least one unmeasured photonic qubit of the entangled state (¶98, “Entanglement between the physical qubits results in expected correlations among measurements on different physical qubits, which enables error correction.”).
Regarding claim 17, the modified Doherty teaches the method according to claim 15, and further discloses wherein at least one photonic multiqubit state comprises a Bell state (¶128).
Regarding claim 18, the modified Doherty teaches the method according to claim 15, and further discloses wherein at least one photonic multiqubit state comprises a 3-qubit GHZ state (¶42, ¶169, ¶188, and Fig. 18).
Regarding claim 19, the modified Doherty teaches the method according to claim 15, and further discloses wherein the optical modes are spatial modes (¶57).
Regarding claim 11, the modified Doherty teaches the apparatus according to claim 10, wherein the interferometer is a time bin interferometer (Figs. 3, ¶23, Mach-Zehnder interferometers; ¶13, “Some embodiments relate to a method that can include receiving, at a plurality of fusion sites, a first plurality of quantum systems, wherein each quantum system of the first plurality of quantum systems includes a plurality of GKP qubits in an entangled state, and wherein respective quantum systems of the first plurality of quantum systems are independent quantum systems that are not entangled with one another. For each of the plurality of fusion sites, a homodyne measurement operation can be selected to be performed by a reconfigurable fusion circuit on respective GKP qubits from two or more of the quantum systems of the first plurality of quantum systems, thereby generating measurement outcome data”; ¶67, “For instance, active multiplexing schemes that employ log-tree, generalized Mach-Zehnder interferometers …”; and ¶209, “Resource state generator 2806 can incorporate CZ gates (e.g., instances of circuit 1700 described above), 3-GHZ state generators (e.g., circuit 1800), and/or fusion circuits (e.g., any of circuits 1900, 2000, 2100, 2200) to create resource states, which in this example are quantum systems of entangled GKP qubits … Fusion network router 2808 can include a set of switches, delay lines, and/or other components that direct qubits of particular resource states to fusion sites within fusion unit 2810 with appropriate timing to implement a particular fusion network. For instance, fusion network router 2808 can include delay lines (which can be lengths of optical fiber or other waveguides) to delay selected qubits from resource states generated during one operating cycle of resource state generator 2806 until a later operating cycle, thereby supporting timelike fusion”, i.e. time-bin encoding into early and late windows).
Allowable Subject Matter
Claims 12-14 are 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.
Regarding claim 12, the modified Doherty teaches the apparatus according to claim 11, wherein the time bin interferometer comprises at least one temporal mode coupling device, and wherein a temporal mode coupling device comprises a beamsplitter and a delay line, the delay line configured to connect one input port of the beamsplitter with one output port of the beamsplitter (Fig. 28, ¶207-209).
The modified Doherty does not explicitly show a reconfigurable beam splitter. The prior art when taken alone or in combination does not remedy this deficiency. Therefore the claim is allowable over the prior art.
Regarding claims 13 and 14, the dependent claims depend from a claim that contains allowable subject matter and are therefore allowable.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to COLLIN X BEATTY whose telephone number is (571)270-1255. The examiner can normally be reached M - F, 10am - 6pm.
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/COLLIN X BEATTY/Primary Examiner, Art Unit 2872
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