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 .
This action is responsive to claims filed on 4/17/2023.
Claims 16-30 are presented for examination.
Priority
Acknowledgment is made of applicant's claim for priority to a prior filed foreign application no. EP 20202922.9, filed 10/20/2020.
Acknowledgment is made of applicant's claim for benefit of a prior filed International Application PCT/IB2021/059068, filed 10/2/2021.
Information Disclosure Statement
The information disclosure statements (IDS) submitted on 4/17/2023 and 5/3/2023 have been considered by the examiner.
Claim Rejections - 35 USC § 103
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.
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, 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.
Claims 16-17, and 19-30 are rejected under 35 U.S.C. 103 as being unpatentable over Ollikainen, “Two-qubit gates in a microwave photonic quantum computer” (2015) pages 1-62, in view of Gu et al., “Microwave photonics with superconducting quantum circuits” (2017) pages 1-68.
Regarding independent claim 16, Ollikainen teaches a quantum computing circuit for performing state operations on qubits (page 2 In this thesis we show how these properties can be utilized in the creation of entangling two-qubit quantum gates in a microwave photonic quantum computer), the quantum computing circuit comprising: a dual-rail structure comprising a set of dual-rail transmission-line elements, a respective dual-rail transmission-line element comprising a first transmission line and a second transmission line for allowing microwave photons to propagate through the first and/or second transmission lines (page 8 Section 2.2.1 Dual-rail representation anticipates the dual-rail structure for encoding qubits using microwave photons as flying qubits, defines the qubit basis states by a single photon propagating in one of two physically separated waveguides (transmission lines), where the state depends on which waveguide the photon propagates in), a respective propagating microwave photon having a specific quantum state, and encoding a qubit, the quantum state depending at least on which one of the first and second transmission lines the respective microwave photon propagates (page 8 Section 2.2.1 discusses single photon propagating in one of the two waveguides so that eigenstates of the Hamiltonian describes the system); a set of single-qubit gates, the respective single-qubit gate comprising a) a first phase shifter, a second phase shifter, and a first directional coupler, or b) a first directional coupler, a second directional coupler, and a first phase shifter (pages 8-9 Section 2.2.2 details construction of an arbitrary single-qubit gate U using equation (2.24) and how to construct the general 2x2 unitary matrix using solely tuneable phase shifters and constant 50:50 beam splitters. This construction is presented in equation (2.25) wherein the structure inherently demonstrates a circuit composed of three R phase shifters and two B 50:50 beam splitters (directional couplers) arranged in sequence. Option (a) and (b) are structurally simpler subsets or variations of the functionality already taught for building any arbitrary single-qubit operation using the two fundamental components R phase shifters and B 50:50 beam splitters), the respective phase shifter being configured to introduce a phase shift to a carrier wave of the microwave photon propagating through the respective phase shifter (pages 8-9 Section 2.2.2 describes that after passing through the first waveguide, photons acquire a phase shift due to the retarding material implementing the phase shifter), the respective directional coupler being configured to transfer or partially transfer a respective microwave photon propagating through the respective single-qubit gate from the first transmission line to the second transmission line, or vice versa (page 9 Section 2.2.2 describes directional coupler beam splitters transferring/partially transferring the photon through corresponding quantum gate); and a set of two-qubit gates, such that the respective two-qubit gate is configured to phase-shift a first input microwave photon and a second input microwave photon of the respective two-qubit gate with respect to other photons propagating in the quantum computing circuit (ABSTRACT thesis is dedicated to demonstrating how to create entangling two-qubit gates in a microwave photonic computer by inducing a photon-number-dependent phase shift nonlinearity. This function is equivalent to the required conditional phase shift two-qubit gate configuration).
Ollikainen does not expressly teach the respective two-qubit gate comprising an artificial atom and an oscillator.
However, Gu teaches qubit gates comprising an artificial atom and an oscillator (pages 4-13 Section 2 cavity QED (CQED) (qubit gates) architecture for light-matter interaction with vacuum Rabi oscillation effect to introduce this phase shift, a phenomenon grounded in the Jaynes-Cummings model as resulting from coupling atoms (qubits) and resonators (oscillators). In CQED, superconducting artificial atoms qubits are intentionally coupled to resonators/oscillators).
Because Ollikainen and Gu address the issue of microwave photonics and qubits, accordingly, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate qubit gates comprising an artificial atom and an oscillator as suggested by Gu into Ollikainen’s quantum computing circuit, with a reasonable expectation of success, such that the functional goal of Ollikainen’s creating a conditional phase shift/nonlinearity for two photons is combined with the standard, widely known structural means taught by Gu of an artificial atom coupled to a resonator/oscillator relying on the vacuum Rabi oscillation effect to achieve that goal in the flying-qubit context to teach a set of two-qubit gates, the respective two-qubit gate comprising an artificial atom and an oscillator such that the respective two-qubit gate is configured to phase-shift a first input microwave photon and a second input microwave photon of the respective two-qubit gate with respect to other photons propagating in the quantum computing circuit. This modification would have been motivated by the desire speed up applications ranging from microwave photonics to superconducting quantum information processing (Gu ABSTRACT).
Regarding dependent 17, Ollikainen, in view of Gu, teach the quantum computing circuit according to claim 16, wherein at least one of the first phase shifter, the second phase shifter, the first directional coupler, and the second directional coupler comprises metamaterial to reduce the wavelength of the microwave photon propagating through the respective phase shifter and/or the directional coupler (see Ollikainen pages 8-9 Section 2.2.2 suggest phase shifter in dual-rail representation implemented with retarding material to result in a shift in frequency of photon propagating through the respective phase shifter).
Regarding dependent claim 19, Ollikainen, in view of Gu, teach the quantum computing circuit according to claim 16, wherein the respective directional coupler is configured as a narrowed section of the single-qubit gate, in which the first and second transmission lines are close enough to each other for the evanescent field of the respective microwave photon propagating in one of the first and second transmission lines to be present in the other transmission line (see Ollikainen page 9 requires the function of a beam splitter (wherein the respective directional coupler) to transfer or partially transfer photons (the evanescent field of the respective microwave photon propagating in one of the first and second transmission lines to be present in the other transmission line) wherein Gu page 13 Section 3.1 one implementation of a microwave beam splitter involves simply putting two transmission lines close to each other over a short distance. This close proximity is the physical manifestation that allows the evanescent field interaction claimed).
Regarding dependent claim 20, Ollikainen, in view of Gu, teach the quantum computing circuit according to claim 16, wherein the first transmission line or the second transmission line comprises the first and second phase shifters, or the first transmission line comprises one of the first and second phase shifters, while the second transmission line comprises the other phase shifter (see Ollikainen page 9 defines the single-qubit operation using phase shifters by having them retard one of the two modes with respect to the other, and models arbitrary single-qubit gates requiring the use of multiple phase shifter elements R along with directional couplers B. The flexible placement of phase shifters within the first and second transmission lines is suggested).
Regarding dependent claim 21, Ollikainen, in view of Gu, teach the quantum computing circuit according to claim 16, wherein the respective two-qubit gate comprises a first input coupled to a first or second transmission line of a first dual-rail transmission-line element, and a second input coupled to a first or second transmission line of a second, different dual-rail transmission-line element (see Ollikainen page 55 Section 5.2 defines the two-qubit computational basis using four separate input creation operators representing two flying qubits in the dual-rail scheme. This operational requirement inherently dictates that the two-qubit gate must be coupled to lines belonging to the two different dual-rail elements. Thus, the requirement that the two-qubit gate inputs couple to separate dual-rail transmission elements is taught).
Regarding dependent claim 22, Ollikainen, in view of Gu, teach the quantum computing circuit according to claim 21, wherein the transmission lines coupled to the two-qubit gate cross each other, or the transmission lines are coupled to the two-qubit gate without crossing each other (see Ollikainen page 56 Figure 5.8 a conditional phase CPS shift two-qubit gate with transmission lines without crossing each other).
Regarding dependent claim 23, Ollikainen, in view of Gu, teach the quantum computing circuit according to claim 16, wherein the artificial atom is coupled to the oscillator by a coupling capacitor (Cg) (see Gu page 17 Section 4 superconducting artificial atoms (qubits) are typically coupled to a resonator (oscillator) via a capacitor), and wherein the oscillator comprises a resonator inductor (Lr) in a parallel configuration with a resonator capacitor (Cr) (see Gu page 11 Section 2.7 states that the simplest resonator is the LC circuit, consisting of a capacitor (C) and an inductor (L)).
Regarding dependent claim 24, Ollikainen, in view of Gu, teach the quantum computing circuit according to claim 16, wherein the artificial atom comprises an artificial atom capacitor (Cb) in a parallel configuration with one or more Josephson junctions (see Gu page 63 Section A.2 explains that superconducting qubits (artificial atoms) are derived from the Cooper-pair box (CPB) and page 8 that the Transmon (a low-noise extension) consists of Josephson junctions shunted by a large capacitor. This aligns directly with the requirement that the artificial atom comprises a capacitor in parallel with Josephson junctions).
Regarding dependent claim 25, Ollikainen, in view of Gu, teach the quantum computing circuit according to claim 16, wherein the resonant angular frequency of the oscillator equals the angular frequency of a transition between energy levels 1 and 2 in the artificial atom or the resonant angular frequency differs from the angular frequency of a transition between energy levels 1 and 2 of the artificial atom by less than twice the coupling rate between the oscillator and the artificial atom (see Gu pages 18-19 Section 4.2 discusses the strong-coupling regime, which is reached when the coherent interaction is maximized, notably mentioning the resonant case which results in vacuum Rabi oscillations. Operating the system in or near resonance is a necessary and obvious choice to maximize coherent interaction, as detailed in the Jaynes-Cummings model context. Thus, the relation between the oscillator resonant frequency and the atom transition frequency defining the resonant and near-resonant regimes is suggested).
Regarding dependent claim 26, Ollikainen, in view of Gu, teach the quantum computing circuit according to claim 16, wherein at least one of the single-qubit gates and/or at least one of the two-qubit gates is programmable, in particular at least one of the single-qubit gates and/or at least one of the two-qubit gates is programmable by a magnetic flux (see Ollikainen page 9 details that the required single-qubit gates employ tunable phase shifters and Gu pages 6-7 Section 2.2.2 provides the primary mechanism for achieving tunability in superconducting circuits, noting that the energy levels (and thus frequency) of flux qubits can be adjusted by external magnetic flux, Gu page 12 further details that SQUIDs (Josephson devices susceptible to flux) are used to create frequency-tunable transmission-line resonators. Using magnetic flux to control gate elements is a core, known technique in the field of superconducting quantum circuits (SQCs). Thus, the programmability of gates via magnetic flux is taught).
Regarding dependent claim 27, Ollikainen, in view of Gu, teach the quantum computing circuit according to claim 16, wherein the quantum computing circuit further comprises a set of switches and/or a set of multiplexers for selectively feeding microwave photons back to the quantum computing circuit or to another quantum computing circuit (see Gu pages 13-15 Section 3 notes that the experimental toolbox for microwave photonics includes switches and routers (multiplexers), explicitly detailing that Josephson junction-based switches have been successfully developed for controlling signal transport. Thus, the incorporation of switches and multiplexers for routing photons is taught).
Regarding dependent claim 28, Ollikainen, in view of Gu, teach the quantum computing circuit according to claim 27, wherein the quantum computing circuit further comprises a microwave-to-optical photon converter for converting microwave photons into optical photons, and wherein at least one of the multiplexers is an optical multiplexer for multiplexing the converted optical photons (see Gu page 13, page 61 Section 11 discusses the goal of forming hybrid devices leveraging the strengths of different systems, mentions that mechanical resonators can be used for transduction between various quantum systems, including conversion between microwave and optical light. Once the signal is converted to the optical domain, routing it using known optical components (like an optical multiplexer) is a straightforward integration of two known technologies. Thus, the inclusion of a microwave-to-optical converter (transducer) and subsequent optical multiplexing is suggested).
Regarding dependent claim 29, Ollikainen, in view of Gu, teach a quantum processor comprising the quantum computing circuit according to claim 16, and further comprising a single microwave photon generation circuit for generating single microwave photons for the quantum computing circuit, and further comprising a microwave photon detection circuit for detecting microwave photons exiting the quantum computing circuit (see Ollikainen page 7 defines the need to prepare and measure the qubits for quantum computing and Gu pages 43-47 Sections 8-9 describing specialized circuits for single microwave photon generation and microwave photon detection and confirming that these are necessary and integrated components of a functioning quantum processor. Thus, the integration of the quantum circuit with photon generation and detection circuits is taught).
Regarding dependent claim 30, Ollikainen, in view of Gu, teach a method of operating the quantum processor according to claim 29, the method comprising: substantially simultaneously feeding microwave photons from the single microwave photon generation circuit into the quantum computing circuit such that at most one microwave photon is fed per one dual-rail transmission-line element (see Ollikainen page 8 Section 2.2.1 sending at most one photon per dual-rail element is fundamental to the dual-rail qubit encoding); allowing the microwave photons to propagate through the sets of single-qubit gates and the two-qubit gates for performing state operations on the qubits propagating through the sets of first and second transmission lines (see Ollikainen ABSTRACT and Section 2.2 performing state operations using the single- and two-qubit gates is the defined function of the core circuit); and detecting the states of the qubits at the microwave photon detection circuit (see Gu page 47 Section 9 Photon detection detecting the state of the qubits using the detection circuit is the necessary final step).
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Ollikainen in view of Gu, as applied in the rejection of claim 17 above, and further in view of Mirhosseini et al., “Superconducting metamaterials for waveguide quantum electrodynamics” (2018) pages 1-6.
Regarding dependent claim 18, Ollikainen, in view of Gu, teach the quantum computing circuit of claim 17, wherein the respective resonator comprises a capacitor (Cr) arranged in a parallel configuration with a one or more of Josephson junctions or one or more superinductors (see Gu page 8 superconducting quantum circuits (SQCs) are constructed using electronic elements like inductors, capacitors, and Josephson junctions in parallel with a capacitor).
Ollikainen and Gu do not expressly teach wherein the metamaterial comprises electronic components, in particular the metamaterial comprises at least two conductors coupled to each other by a set of resonators.
However, Mirhosseini teaches a metamaterial comprising electronic components, in particular the metamaterial comprises at least two conductors coupled to each other by a set of resonators (pages 2-3 describes the use of lumped-element microwave resonators in to form the metamaterial waveguide consisting of a coplanar waveguide that is periodically loaded with microwave resonators for use with waveguide-qubit coupling).
Because Ollikainen, in view of Gu, and Mirhosseini address the issue of waveguides coupling associated with qubits, accordingly, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate the teachings of a metamaterial comprising electronic components, in particular the metamaterial comprises at least two conductors coupled to each other by a set of resonators as suggested by Mirhosseini in to Ollikainen and Gu’s quantum computing circuit, with a reasonable expectation of success, to teach wherein the metamaterial comprises electronic components, in particular the metamaterial comprises at least two conductors coupled to each other by a set of resonators, wherein the respective resonator comprises a capacitor (Cr) arranged in a parallel configuration with a one or more of Josephson junctions or one or more superinductors. This modification would have been motivated by the desire to enable denser qubit circuits, both spatially and spectrally (Mirhosseini page 3).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Pellerano et al., US 20220094341 A1, (Mar. 24, 2022) (ABSTRACT Quantum circuit assemblies that employ active pulse shaping in order to be able to control states of a plurality of qubits with signal pulses propagated over a shared signal propagation channel are disclosed. An example quantum circuit assembly includes a quantum circuit component that includes a first qubit, associated with a first frequency to control the state of the first qubit, and a second qubit, associated with a second frequency to control the state of the second qubit. A shared transmission channel is coupled to the first and second qubits. The assembly further includes a signal pulse generation circuit, configured to generate a signal pulse to be propagated over the shared transmission channel to control the state of the first qubit, where the signal pulse has a center frequency at the first frequency, a bandwidth that includes the second frequency, and a notch at the second frequency).
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/KC CHEN/Primary Patent Examiner, Art Unit 2143