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, 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 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.
Claim(s) [ 1-2,5,13-18,29-31,34-38, 40-42 ] are rejected under 35 U.S.C. 103 as being unpatentable over [ Otterbach et al. (US 10846366), hereinafter "Otterbach", in view of Gidney (US 11030546), hereinafter "Gidney", in further view of Kandala et al. (US 10755193), hereinafter "Kandala" ].
As per claim 1, Otterbach significantly teaches a method comprising: augmenting a quantum approximate optimization algorithm (QAOA) quantum circuit (The quantum approximate optimization algorithm (QAOA) can be viewed through the lens of probabilistic optimization algorithms. [Otterbach PP 0008]), wherein: the quantum circuit includes a cost layer that implements a unitary generated by a cost Hamiltonian and a mixer layer (prepare the state |ψ(x; θ)⟩ = ∏_{i=1}^p [e^{-i θ_{2i-1} H_D} e^{-i θ_{2i} H_C}] H^{⊗n}|0⟩ [Otterbach PP 0055] The unitary is generated by the cost Hamiltonian H)
Otterbach does not explicitly teach “that implements an XY mixer that connects all qubits in a one-hot encoding block to all other qubits in the encoding block via unitary gates; augmenting the quantum circuit includes adding to the quantum circuit one or more encoders configured to perform unitary mapping of one-hot encoding basis states to basis states of a reduced number of qubits padded with one or more padding qubits in the zero computational basis state, mid-circuit measurements, conditional resets, and one or more decoders configured to perform unitary mapping from the basis states of the reduced number of qubits padded with the one or more padding qubits to one-hot encoding basis states; the mid-circuit measurements are configured to cause one or more quantum processing units (QPUs) to measure one or more qubits of the augmented quantum circuit in the computational basis state; and the one or more conditional resets are configured to reset the augmented quantum circuit without full execution of a variational loop if one or more mid-circuit measurement results indicate that one or more qubits of the augmented quantum circuit are in an invalid state.”
However, Gidney, in an analogous art, teaches that implements an XY mixer that connects all qubits in a one-hot encoding block to all other qubits in the encoding block via unitary gates (The system uses a series of Mk controlled swaps to permute the registers r0 , . . . , rk-1 such that register rl takes the place of register r0 where l represents a superposed integer value of the bottom log k qubits in the address register. [Gidney PP 0071]);
augmenting the quantum circuit includes adding to the quantum circuit one or more encoders configured to perform unitary mapping of one-hot encoding basis states to basis states of a reduced number of qubits padded with one or more padding qubits in the zero computational basis state (the quantum circuit operates on an address register of qubits and a target register of qubits. The state of the address register encodes address information that determines a respective state of the target register. [Gidney PP 0048]), mid-circuit measurements (replacing the sequence of operations with an X basis measurement [Gidney PP 0005])
one or more decoders configured to perform unitary mapping from the basis states of the reduced number of qubits padded with the one or more padding qubits to one-hot encoding basis states (A corresponding table lookup uncompute operation negates the amplitude of the |2⟩ state of the address register [Gidney PP 0050] The uncompute operation reverses the mapping (decoder));
and the one or more conditional resets are configured to reset the augmented quantum circuit without full execution of a variational loop if one or more mid-circuit measurement results indicate that one or more qubits of the augmented quantum circuit are in an invalid state (The classical control system can be configured to check the result of the particular measurement and, if the result is True, cause a Z gate to be applied. [Gidney PP 0045]).
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the QAOA circuit disclosed by Otterbach to incorporate Gidney's teaching of mid circuit measurements and classically controlled operations, in order to improve efficiency and reduce circuit cost (The presently described techniques produce optimized quantum circuits that, when executed, can perform corresponding quantum computations with increased computational efficiency. [Gidney PP 0022]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach's invention.
Otterbach in view of Gidney do not explicitly teach “conditional resets … the mid-circuit measurements are configured to cause one or more quantum processing units (QPUs) to measure one or more qubits of the augmented quantum circuit in the computational basis state;”
However, Kandala, in an analogous art, teaches conditional resets (application 105 resets the qubit/cavity to the ground state for each qubit [Kandala PP 0078]),
the mid-circuit measurements are configured to cause one or more quantum processing units (QPUs) to measure one or more qubits of the augmented quantum circuit in the computational basis state (application 105 resets the qubit/cavity to the ground state for each qubit [Kandala PP 0078]);
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the system of Otterbach and Gidney to incorporate Kandala's teaching of computational basis measurement and qubit reset, in order to improve efficiency and reduce circuit cost (implementation of error mitigation of short-depth quantum computing circuits to significantly enhance the power of near-term quantum computers [Kandala PP 0009]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach and Gidney's invention.
As per claim 2, Otterbach in view of Gidney do not explicitly teach “wherein the mid-circuit measurements are configured to cause the one or more QPUs to measure in the computational basis state one or more qubits of the augmented quantum circuit expected to be in the zero computational basis state.”
However, Kandala, in an analogous art, teaches wherein the mid-circuit measurements are configured to cause the one or more QPUs to measure in the computational basis state one or more qubits of the augmented quantum circuit expected to be in the zero computational basis state (initializing the qubits to a ground state … measuring a state of each qubit to determine the one or more expectation values of interest [Kandala PP 0009]).
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the system of Otterbach and Gidney to incorporate Kandala's teaching of computational basis measurement and qubit reset, in order to improve efficiency and reduce circuit cost (implementation of error mitigation of short-depth quantum computing circuits to significantly enhance the power of near-term quantum computers [Kandala PP 0009]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach and Gidney's invention.
As per claim 5, Otterbach in view of Gidney do not explicitly teach “further comprising validating the quantum circuit and corresponding encodings.”
However, Kandala, in an analogous art, teaches further comprising validating the quantum circuit and corresponding encodings (application 105 determines a number of stretch factors ci such that ci *t0 <coherence times where t0 is a time duration of a microwave pulse of the quantum processor. In one or more embodiments, the application determines the stretch factors based upon the time correlations of the noise and the coherence times. In block 510 , application 105 pre-calibrates primitive gates for each stretch factor ci [Kandala PP 0085]).
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the system of Otterbach and Gidney to incorporate Kandala's teaching of computational basis measurement and qubit reset, in order to improve efficiency and reduce circuit cost (implementation of error mitigation of short-depth quantum computing circuits to significantly enhance the power of near-term quantum computers [Kandala PP 0009]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach and Gidney's invention.
As per claim 13, Otterbach does not explicitly teach “wherein the one or more encoders comprise one or more unary-binary basis change operators, and the one or more decoders are one or more binary-unary basis change operators.”
However, Gidney, in an analogous art, teaches wherein the one or more encoders comprise one or more unary-binary basis change operators, and the one or more decoders are one or more binary-unary basis change operators (A corresponding table lookup uncompute operation negates the amplitude of the |2⟩ state of the address register [Gidney PP 0050] The address register is binary-encoded; the target register can represent unary one-hot states).
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the QAOA circuit disclosed by Otterbach to incorporate Gidney's teaching of mid circuit measurements and classically controlled operations, in order to improve efficiency and reduce circuit cost (The presently described techniques produce optimized quantum circuits that, when executed, can perform corresponding quantum computations with increased computational efficiency. [Gidney PP 0022]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach's invention.
As per claim 14, Otterbach does not explicitly teach “wherein the reduced number of qubits is 1, the one or more padding qubits include k-1 padding qubits, and the augmented quantum circuit includes k qubits.”
However, Gidney, in an analogous art, teaches wherein the reduced number of qubits is 1, the one or more padding qubits include k-1 padding qubits, and the augmented quantum circuit includes k qubits (Every computational basis value of the address register results in a specific computational basis value for registers r0 , . . . , rk-1 [Gidney PP 0072]).
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the QAOA circuit disclosed by Otterbach to incorporate Gidney's teaching of mid circuit measurements and classically controlled operations, in order to improve efficiency and reduce circuit cost (The presently described techniques produce optimized quantum circuits that, when executed, can perform corresponding quantum computations with increased computational efficiency. [Gidney PP 0022]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach's invention.
As per claim 15, Otterbach in view of Gidney do not explicitly teach “wherein the mid- circuit measurements are configured to cause the one or more QPUs to measure one or more of the padding qubits of the augmented quantum circuit in the computational basis state.”
However, Kandala, in an analogous art, teaches wherein the mid- circuit measurements are configured to cause the one or more QPUs to measure one or more of the padding qubits of the augmented quantum circuit in the computational basis state (measuring a state of each qubit [Kandala PP 0009]).
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the system of Otterbach and Gidney to incorporate Kandala's teaching of computational basis measurement and qubit reset, in order to improve efficiency and reduce circuit cost (implementation of error mitigation of short-depth quantum computing circuits to significantly enhance the power of near-term quantum computers [Kandala PP 0009]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach and Gidney's invention.
As per claim 16, Otterbach does not explicitly teach “wherein the augmented quantum circuit comprises one or more ancilla qubits configured to take the mid- circuit measurements.”
However, Gidney, in an analogous art, teaches wherein the augmented quantum circuit comprises one or more ancilla qubits configured to take the mid- circuit measurements (a clean ancilla qubit u prepared in the |1> state [Gidney PP 0057]).
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the QAOA circuit disclosed by Otterbach to incorporate Gidney's teaching of mid circuit measurements and classically controlled operations, in order to improve efficiency and reduce circuit cost (The presently described techniques produce optimized quantum circuits that, when executed, can perform corresponding quantum computations with increased computational efficiency. [Gidney PP 0022]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach's invention.
As per claim 17, Otterbach significantly teaches further comprising compiling the augmented quantum circuit (the Hamiltonian Ĥ and values of the parameters (θ) are encoded into machine instructions [Otterbach PP 0054]).
As per claim 18, Otterbach significantly teaches further comprising executing the compiled quantum circuit using at least the one or more QPUs (the machine instructions generated at 210 can be provided to the QPU 103 shown in FIG. 1, and the QPU can execute the machine instructions [Otterbach PP 0056]).
As per claim 29, Otterbach significantly teaches a system adapted to: augment a quantum approximate optimization algorithm (QAOA) quantum circuit (the Hamiltonian Ĥ and values of the parameters (θ) are encoded into machine instructions [Otterbach PP 0054]), wherein: the quantum circuit includes a cost layer that implements a unitary generated by a cost Hamiltonian and a mixer layer (prepare the state |ψ(x; θ)⟩ = ∏_{i=1}^p [e^{-i θ_{2i-1} H_D} e^{-i θ_{2i} H_C}] H^{⊗n}|0⟩ [Otterbach PP 0055] The unitary is generated by the cost Hamiltonian H)
Otterbach does not explicitly teach “implements an XY mixer that connects all qubits in a one-hot encoding block to all other qubits in the encoding block via unitary gates; augmenting the quantum circuit includes adding to the quantum circuit one or more encoders configured to perform unitary mapping of one-hot encoding basis states to basis states of a reduced number of qubits padded with one or more padding qubits in the zero computational basis state, mid-circuit measurements, conditional resets, and one or more decoders configured to perform unitary mapping from the basis states of the reduced number of qubits padded with the one or more padding qubits to one-hot encoding basis states; the mid-circuit measurements are configured to cause one or more quantum processing units (QPUs) to measure one or more qubits of the augmented quantum circuit in the computational basis state; and the one or more conditional resets are configured to reset the augmented quantum circuit without full execution of a variational loop if one or more mid-circuit measurement results indicate that one or more qubits of the augmented quantum circuit are in an invalid state.”
However, Gidney, in an analogous art, teaches implements an XY mixer that connects all qubits in a one-hot encoding block to all other qubits in the encoding block via unitary gates (The system uses a series of Mk controlled swaps to permute the registers r0 , . . . , rk-1 such that register rl takes the place of register r0 where l represents a superposed integer value of the bottom log k qubits in the address register. [Gidney PP 0071]);
augmenting the quantum circuit includes adding to the quantum circuit one or more encoders configured to perform unitary mapping of one-hot encoding basis states to basis states of a reduced number of qubits padded with one or more padding qubits in the zero computational basis state, mid-circuit measurements, conditional resets, and one or more decoders configured to perform unitary mapping from the basis states of the reduced number of qubits padded with the one or more padding qubits to one-hot encoding basis states (operates on an address register of qubits and a target register of qubits. The state of the address register encodes address information that determines a respective state of the target register. [Gidney PP 0048], replacing the sequence of operations with an X basis measurement [Gidney PP 0005], A corresponding table lookup uncompute operation negates the amplitude of the |2⟩ state of the address register [Gidney PP 0050] The uncompute operation reverses the mapping (decoder));
the one or more conditional resets are configured to reset the augmented quantum circuit without full execution of a variational loop if one or more mid-circuit measurement results indicate that one or more qubits of the augmented quantum circuit are in an invalid state (The classical control system can be configured to check the result of the particular measurement and, if the result is True, cause a Z gate to be applied. [Gidney PP 0045]).
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the QAOA circuit disclosed by Otterbach to incorporate Gidney's teaching of mid circuit measurements and classically controlled operations, in order to improve efficiency and reduce circuit cost (The presently described techniques produce optimized quantum circuits that, when executed, can perform corresponding quantum computations with increased computational efficiency. [Gidney PP 0022]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach's invention.
Otterbach in view of Gidney do not explicitly teach “the mid-circuit measurements are configured to cause one or more quantum processing units (QPUs) to measure one or more qubits of the augmented quantum circuit in the computational basis state;”
However, Kandala, in an analogous art, teaches the mid-circuit measurements are configured to cause one or more quantum processing units (QPUs) to measure one or more qubits of the augmented quantum circuit in the computational basis state (application 105 measures qubit states of each qubit to determine the expectation values of interest [Kandala PP 0078]);
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the system of Otterbach and Gidney to incorporate Kandala's teaching of computational basis measurement and qubit reset, in order to improve efficiency and reduce circuit cost (implementation of error mitigation of short-depth quantum computing circuits to significantly enhance the power of near-term quantum computers [Kandala PP 0009]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach and Gidney's invention.
As per claim 30, Otterbach significantly teaches a method comprising: compiling an augmented quantum approximate optimization algorithm (QAOA) quantum circuit (the Hamiltonian Ĥ and values of the parameters (θ) are encoded into machine instructions [Otterbach PP 0054]), wherein the augmented quantum circuit includes a cost layer that implements a unitary generated by a cost Hamiltonian, a mixer layer (prepare the state |ψ(x; θ)⟩ = ∏_{i=1}^p [e^{-i θ_{2i-1} H_D} e^{-i θ_{2i} H_C}] H^{⊗n}|0⟩ [Otterbach PP 0055] The unitary is generated by the cost Hamiltonian H)
Otterbach does not explicitly teach “that implements an XY mixer that connects all qubits in a one-hot encoding block to all other qubits in the encoding block via unitary gates, one or more encoders, mid-circuit measurements, and conditional resets; and executing the compiled quantum circuit, wherein executing the compiled quantum circuit comprises: using the one or more encoders configured to perform unitary mapping of one-hot encoding basis states to basis states of a reduced number of qubits padded with one or more padding qubits in the zero computational basis state; using at least one or more quantum processing units (QPUs) to take the mid-circuit measurements by measuring one or more qubits of the compiled quantum circuit in the computational basis state; determining that one or more mid-circuit measurement results indicate that one or more qubits of the compiled quantum circuit are in an invalid state; and if the one or more mid-circuit measurement results are determined to indicate that the one or more qubits of the compiled quantum circuit are in the invalid state, resetting the compiled quantum circuit without full execution of a variational loop.”
However, Gidney, in an analogous art, teaches that implements an XY mixer that connects all qubits in a one-hot encoding block to all other qubits in the encoding block via unitary gates (The system uses a series of Mk controlled swaps to permute the registers r0 , . . . , rk-1 such that register rl takes the place of register r0 where l represents a superposed integer value of the bottom log k qubits in the address register. [Gidney PP 0071]), one or more encoders (a quantum circuit that computes and uncomputes a table lookup. In these implementations, the quantum circuit operates on an address register of qubits and a target register of qubits. [Gidney PP 0048]), mid-circuit measurements (replacing the sequence of operations with an X basis measurement [Gidney PP 0005])
executing the compiled quantum circuit, wherein executing the compiled quantum circuit comprises: using the one or more encoders configured to perform unitary mapping of one-hot encoding basis states to basis states of a reduced number of qubits padded with one or more padding qubits in the zero computational basis state (The state of the address register encodes address information that determines a respective state of the target register. [Gidney PP 0048]);
determining that one or more mid-circuit measurement results indicate that one or more qubits of the compiled quantum circuit are in an invalid state (The classical control system can be configured to check the result of the particular measurement and, if the result is True, cause a Z gate to be applied. [Gidney PP 0045]);
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the QAOA circuit disclosed by Otterbach to incorporate Gidney's teaching of mid circuit measurements and classically controlled operations, in order to improve efficiency and reduce circuit cost (The presently described techniques produce optimized quantum circuits that, when executed, can perform corresponding quantum computations with increased computational efficiency. [Gidney PP 0022]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach's invention.
Otterbach in view of Gidney do not explicitly teach “conditional resets; using at least one or more quantum processing units (QPUs) to take the mid-circuit measurements by measuring one or more qubits of the compiled quantum circuit in the computational basis state; and if the one or more mid-circuit measurement results are determined to indicate that the one or more qubits of the compiled quantum circuit are in the invalid state, resetting the compiled quantum circuit without full execution of a variational loop.”
However, Kandala, in an analogous art, teaches conditional resets (application 105 measures qubit states of each qubit to determine the expectation values of interest [Kandala PP 0078]);
using at least one or more quantum processing units (QPUs) to take the mid-circuit measurements by measuring one or more qubits of the compiled quantum circuit in the computational basis state (measuring a state of each qubit to determine the one or more expectation values of interest [Kandala PP 0009]); and
if the one or more mid-circuit measurement results are determined to indicate that the one or more qubits of the compiled quantum circuit are in the invalid state, resetting the compiled quantum circuit without full execution of a variational loop (In block 426 , application 105 resets the qubit/cavity to the ground state for each qubit. [Kandala PP 0078]).
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the system of Otterbach and Gidney to incorporate Kandala's teaching of computational basis measurement and qubit reset, in order to improve efficiency and reduce circuit cost (implementation of error mitigation of short-depth quantum computing circuits to significantly enhance the power of near-term quantum computers [Kandala PP 0009]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach and Gidney's invention.
As per claim 31, Otterbach in view of Gidney do not explicitly teach “wherein the mid-circuit measurements measure one or more qubits of the compiled quantum circuit expected to be in the zero computational basis state.”
However, Kandala, in an analogous art, teaches wherein the mid-circuit measurements measure one or more qubits of the compiled quantum circuit expected to be in the zero computational basis state (In block 418 , application 105 initializes the qubits in their respective ground states. [Kandala PP 0078]).
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the system of Otterbach and Gidney to incorporate Kandala's teaching of computational basis measurement and qubit reset, in order to improve efficiency and reduce circuit cost (implementation of error mitigation of short-depth quantum computing circuits to significantly enhance the power of near-term quantum computers [Kandala PP 0009]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach and Gidney's invention.
As per claim 34, Otterbach does not explicitly teach “wherein executing the compiled quantum circuit comprises using an encoder to perform a one- hot encoding of variables.”
However, Gidney, in an analogous art, teaches wherein executing the compiled quantum circuit comprises using an encoder to perform a one- hot encoding of variables (The controlled S operation 510 shifts the |1> state of r0 to position l, producing a one-hot unary encoding of the value in the bottom log k qubits in the address register 504 . [Gidney PP 0076]).
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the QAOA circuit disclosed by Otterbach to incorporate Gidney's teaching of mid circuit measurements and classically controlled operations, in order to improve efficiency and reduce circuit cost (The presently described techniques produce optimized quantum circuits that, when executed, can perform corresponding quantum computations with increased computational efficiency. [Gidney PP 0022]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach's invention.
As per claim 35, Otterbach does not explicitly teach “wherein the reduced number of qubits is 1, the one or more padding qubits include k-1 padding qubits, and the compiled quantum circuit includes k qubits.”
However, Gidney, in an analogous art, teaches wherein the reduced number of qubits is 1, the one or more padding qubits include k-1 padding qubits, and the compiled quantum circuit includes k qubits (to compute a table lookup a system allocates qubit registers r0 , . . . rk-1 , where each qubit register ri includes M clean qubits initialized to a first state, e.g., a 0 state. [Gidney PP 0070]).
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the QAOA circuit disclosed by Otterbach to incorporate Gidney's teaching of mid circuit measurements and classically controlled operations, in order to improve efficiency and reduce circuit cost (The presently described techniques produce optimized quantum circuits that, when executed, can perform corresponding quantum computations with increased computational efficiency. [Gidney PP 0022]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach's invention.
As per claim 36, Otterbach in view of Gidney do not explicitly teach “wherein the one or more measured qubits are one or more of the padding qubits of the compiled quantum circuit.”
However, Kandala, in an analogous art, teaches wherein the one or more measured qubits are one or more of the padding qubits of the compiled quantum circuit (measuring a state of each qubit to determine the one or more expectation values of interest [Kandala PP 0009] padding qubits are part of the quantum circuit).
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the system of Otterbach and Gidney to incorporate Kandala's teaching of computational basis measurement and qubit reset, in order to improve efficiency and reduce circuit cost (implementation of error mitigation of short-depth quantum computing circuits to significantly enhance the power of near-term quantum computers [Kandala PP 0009]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach and Gidney's invention.
As per claim 37, Otterbach does not explicitly teach “wherein executing the compiled quantum circuit comprises using one or more decoders to perform unitary mapping from the basis states of the reduced number of qubits padded with the one or more padding qubits to one-hot encoding basis states.”
However, Gidney, in an analogous art, teaches wherein executing the compiled quantum circuit comprises using one or more decoders to perform unitary mapping from the basis states of the reduced number of qubits padded with the one or more padding qubits to one-hot encoding basis states (Uncomputing a table lookup can be defined as applying the transformation ∑_{j=1}^d |j⟩|f(j)⟩ ↦ ∑_{j=1}^d |j⟩|0⟩. [Gidney PP 0053]).
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the QAOA circuit disclosed by Otterbach to incorporate Gidney's teaching of mid circuit measurements and classically controlled operations, in order to improve efficiency and reduce circuit cost (The presently described techniques produce optimized quantum circuits that, when executed, can perform corresponding quantum computations with increased computational efficiency. [Gidney PP 0022]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach's invention.
As per claim 38, Otterbach does not explicitly teach “wherein executing the compiled quantum circuit comprises using one or more ancilla qubits to take the mid-circuit measurements.”
However, Gidney, in an analogous art, teaches wherein executing the compiled quantum circuit comprises using one or more ancilla qubits to take the mid-circuit measurements (The system applies a CNOT operation to qubit q in the address register that represents the least significant bit and a clean ancilla qubit u prepared in the |1> state [Gidney PP 0057]).
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the QAOA circuit disclosed by Otterbach to incorporate Gidney's teaching of mid circuit measurements and classically controlled operations, in order to improve efficiency and reduce circuit cost (The presently described techniques produce optimized quantum circuits that, when executed, can perform corresponding quantum computations with increased computational efficiency. [Gidney PP 0022]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach's invention.
As per claim 40, Otterbach significantly teaches a system adapted to: compile an augmented quantum approximate optimization algorithm (QAOA) quantum circuit (a hybrid computer system may comprise a quantum processor unit (QPU) and one or more classical processor units, the hybrid computer system being configured to perform operations comprising: obtaining a first set of output values from a first execution of a quantum approximate optimization algorithm (QAOA) [Otterbach PP 0010]), wherein the augment quantum circuit includes a cost layer that implements a unitary generated by a cost Hamiltonian, a mixer layer (prepare the state |ψ(x; θ)⟩ = ∏_{i=1}^p [e^{-i θ_{2i-1} H_D} e^{-i θ_{2i} H_C}] H^{⊗n}|0⟩ [Otterbach PP 0055] The unitary is generated by the cost Hamiltonian H)
Otterbach does not explicitly teach “that implements an XY mixer that connects all qubits in a one-hot encoding block to all other qubits in the encoding block via unitary gates, one or more encoders, mid-circuit measurements, and conditional resets; and execute the compiled quantum circuit, wherein the system, in executing the compiled quantum circuit, is adapted to: use the one or more encoders configured to perform unitary mapping of one-hot encoding basis states to basis states of a reduced number of qubits padded with one or more padding qubits in the zero computational basis state; use at least one or more quantum processing units (QPUs) to take the mid-circuit measurements by measuring one or more qubits of the compiled quantum circuit in the computational basis state; determine that one or more mid-circuit measurement results indicate that one or more qubits of the compiled quantum circuit are in an invalid state; and if the one or more mid-circuit measurement results are determined to indicate that the one or more qubits of the compiled quantum circuit are in the invalid state, reset the compiled quantum circuit without full execution of a variational loop.”
However, Gidney, in an analogous art, teaches that implements an XY mixer that connects all qubits in a one-hot encoding block to all other qubits in the encoding block via unitary gates (The system uses a series of Mk controlled swaps to permute the registers r0 , . . . , rk-1 such that register rl takes the place of register r0 where l represents a superposed integer value of the bottom log k qubits in the address register. [Gidney PP 0071]), one or more encoders (The system then computes the table lookup with address h targeting the registers r0 , . . . , rk-1 [Gidney PP 0070]), mid-circuit measurements (replacing the sequence of operations with an X basis measurement [Gidney PP 0005])
execute the compiled quantum circuit, wherein the system, in executing the compiled quantum circuit, is adapted to: use the one or more encoders configured to perform unitary mapping of one-hot encoding basis states to basis states of a reduced number of qubits padded with one or more padding qubits in the zero computational basis state (The system then computes the table lookup with address h targeting the registers r0 , . . . , rk-1 , where h represents the superposed integer value of the top ┌log(d/k)┐ qubits of the address register. [Gidney PP 0070]);
determine that one or more mid-circuit measurement results indicate that one or more qubits of the compiled quantum circuit are in an invalid state (The classical control system can be configured to check the result of the particular measurement and, if the result is True, cause a Z gate to be applied. [Gidney PP 0045]);
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the QAOA circuit disclosed by Otterbach to incorporate Gidney's teaching of mid circuit measurements and classically controlled operations, in order to improve efficiency and reduce circuit cost (The presently described techniques produce optimized quantum circuits that, when executed, can perform corresponding quantum computations with increased computational efficiency. [Gidney PP 0022]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach's invention.
Otterbach in view of Gidney do not explicitly teach “conditional resets; use at least one or more quantum processing units (QPUs) to take the mid-circuit measurements by measuring one or more qubits of the compiled quantum circuit in the computational basis state; and if the one or more mid-circuit measurement results are determined to indicate that the one or more qubits of the compiled quantum circuit are in the invalid state, reset the compiled quantum circuit without full execution of a variational loop.”
However, Kandala, in an analogous art, teaches conditional resets (application 105 measures qubit states of each qubit to determine the expectation values of interest [Kandala PP 0078]);
use at least one or more quantum processing units (QPUs) to take the mid-circuit measurements by measuring one or more qubits of the compiled quantum circuit in the computational basis state (In block 424 , application 105 measures qubit states of each qubit to determine the expectation values of interest. [Kandala PP 0078]); and
if the one or more mid-circuit measurement results are determined to indicate that the one or more qubits of the compiled quantum circuit are in the invalid state, reset the compiled quantum circuit without full execution of a variational loop (In block 426 , application 105 resets the qubit/cavity to the ground state for each qubit. [Kandala PP 0078]).
Therefore, it would have been obvious for one of ordinary skill in the art to have modified the system of Otterbach and Gidney to incorporate Kandala's teaching of computational basis measurement and qubit reset, in order to improve efficiency and reduce circuit cost (implementation of error mitigation of short-depth quantum computing circuits to significantly enhance the power of near-term quantum computers [Kandala PP 0009]). Applying these teachings would have been a predictable variation for someone of ordinary skill in the art to Otterbach and Gidney's invention.
As per claim 41, Otterbach significantly teaches processing circuitry (a hybrid computer system may comprise a quantum processor unit (QPU) and one or more classical processor units [Otterbach PP 0010]); and
a memory containing instructions executable by said processing circuitry (using a Bayesian optimizer running on the one or more classical processor units [Otterbach PP 0009]), whereby said system is operative to perform the compiling and the executing of the quantum circuit (the hybrid computer system being configured to perform operations comprising: obtaining a first set of output values from a first execution of a quantum approximate optimization algorithm (QAOA) [Otterbach PP 0010]).
As per claim 42, Otterbach significantly teaches processing circuitry (a hybrid computer system may comprise a quantum processor unit (QPU) and one or more classical processor units [Otterbach PP 0010]); and
a memory containing instructions executable by said processing circuitry (using a Bayesian optimizer running on the one or more classical processor units [Otterbach PP 0009]), whereby said system is operative to perform the augmenting (the hybrid computer system being configured to perform operations comprising: obtaining a first set of output values from a first execution of a quantum approximate optimization algorithm (QAOA) [Otterbach PP 0010]).
Conclusion
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/KAREEM FUAD ALHWAMDEH/Examiner, Art Unit 2112
/ALBERT DECADY/Supervisory Patent Examiner, Art Unit 2112
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