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 .
Response to Arguments
Applicant's arguments filed 8/27/2026 are persuasive. The claims overlap and there is no election requirement as long as the claims stay overlapping.
Note on prior art
For claims 4 and 13, the prior art of record does not teach or makes obvious “measurement loops of the first and second measurement circuits are distributed so as to minimize a length of the sequence while subjecting no qubit to redundant measurement.” Specifically, Chao teaches “minimized measurement sequences for syndrome extraction…” But none of the prior art teaches that “no qubit” is subjected to “redundant measurement.”
For claims 5 and 13, the prior art of record does not teach or make obvious “the one- and two-qubit projective-measurement loops of the second measurement circuit are obtained from those of the first measurement circuit by a ninety-degree basis rotation and interchange of corresponding operators in the one- and two-qubit projective measurement loops.” Specifically, there is no ninety-degree basis rotation.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
Claims 1-20 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the enablement requirement. The claims contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention. The Wands factors support a finding of an undue amount of experimentation to make or use the invention:
The claims are broad because they encompass implementation of Majorana-tetron lattices generally, including but not limited to the illustrated (non-enabled) single-rail and double-rail examples;
The nature of the invention is complex and unpredictable because it concerns physical quantum-computing hardware using topological superconductors, semiconductor rails, Majorana-tetron lattices , and projective measurements;1
The state of the prior art is uncertain about the existence of the working measurement circuits and measurement methods of the Majorana lattices;2
The level of ordinary skill is high compared to other arts but low with respect to generating useful and operational measurement circuits for Majorana-tetron lattices, this level of skill in the art requires undue experimentation to make and use the claimed invention;
The level of predictability in the art of measuring Majorana lattices is close to zero, and it is a highly experimental art, requiring undue experimentation without significant guidance;
The specification provides block drawings and desired measurement schedules, but does not provide working examples of a quantum computer that performs the claimed Majorana-tetron measurement circuits;34
The quantity of experimentation needed to make and use the claimed invention across its full scope would be undue in view of the limited implementation guidance provided.5
Therefore, the specification does not teach one of ordinary skill in the art how to make and use the full scope of the claimed invention without undue experimentation.
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.
Claims 1-3, 6-12 and 14-20 are rejected under 35 U.S.C. 103 as being unpatentable over Optimization of the surface code design for Majorana-based qubits by Chao et al, US20180052806A1 to Hastings et al, and US20210019223A1 to Chamberland et al.
Chao teaches claim 1. A method for implementing a measurement circuit of a surface code on a plaquette of qubits of a Majorana(Chao abs “we present surface code error-correction schemes using only Pauli measurements on single qubits and on pairs of nearest-neighbor qubits.” Chao sec. 1 p. 1 “reliable measurements of qubit Pauli operators—which can be realized by gathering relevant constituent Majoranas…” Chao sec. III “The surface code [1–3] encodes one logical qubit into a grid of d × d physical qubits as shown in Fig. 2.”)
distributing among a sequence of time steps a set of one-qubit projective-measurement loops (Chao sec. IV “Here we consider how to implement the weight-four X⊗4 andZ⊗4 stabilizer measurements required for the surface code using measurement-based qubits.” Chao fig. 6, below, “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements.”)
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distributing among the sequence of time steps a set of two-qubit projective-measurement loops on each of four data qubits of the plaquette together (Chao fig. 6 “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements.” Chao fig. 7 “FIG. 7. Schedules for the joint Pauli measurements between data qubits and ancillas…” Chao’s plaquette contains four data qubits.)
distributing among the sequence of time steps a set of two-qubit projective measurement loops on two or more auxiliary-qubit pairs(Chao fig. 6 “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements…. the two connected ancillas are used together for a single plaquette measurement” Chao fig. 7 “FIG. 7. Schedules for the joint Pauli measurements between data qubits and ancillas…”)
advancing through each of the time steps of the sequence, executing the one- and two-qubit projective measurements distributed therein, (Chao fig. 6 “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements.” Chao fig. 6 show stepping through 16 time steps taking 10 single qubit measurements and 8 joint measurements.) such measurements generating measurement of a stabilizer operator of the surface code. (Chao fig. 6 “FIG.6. Measurement-based circuits which implement the X ⊗ 4 stabilizer measurement.”)
Chao doesn’t teach a tetron lattice.
However, Hastings teaches plaquette of qubits of a Majorana-tetron lattice (Hastings para 17 “mesoscopic superconducting islands that each host 4 Majorana zero modes (MZMs), a unit that is collectively referred to herein as a “Majorana Tetron qubit” (also known as a ‘Majorana Quad qubit”).”)
Hastings, Chao and the claims all measure Majoranas zero modes. It would have been obvious to a person having ordinary skill in the art, at the time of filing, to use a tetron lattice “Four is the smallest number of MZMs that supports a single computational qubit, which is encoded in the nonlocal (topological) state space of the MZMs…” Hastings para 17.
Chao doesn’t teach the number of auxiliary qubits.
However, Chamberland teaches on each of three auxiliary qubits of the plaquette;… distributing among the sequence of time steps a set… measurement loops on each … data qubits of the plaquette together with one of the three auxiliary qubits… auxiliary-qubit pairs selected from the three auxiliary qubits of the plaquette… (Chamberland para 49 “performing measurements includes measuring an error in a quantum circuit using at least one ancilla qubit and at least two flag qubits, the quantum circuit comprising a sub-plurality of data qubits in the plurality of data qubits and a plurality of gates.” The claims don’t limit the scope to only “one of the three auxiliary qubits” or only one “auxiliary-qubit pairs”, therefore when Chamberland teaches using three ancilla qubits for the measurement of the data qubit, Chamberland teaches the broad scope of the claim element.)
Chamberland, Chao and the claims all have ancilla qubits to assist measuring data qubits. It would have been obvious to a person having ordinary skill in the art, at the time of filing, to distribute measurements among time steps of the data qubits together with at least three auxiliary qubits so that “the extra ancillas can also become resources for the decoding process.” Chamberland para 44.
Hastings teaches claim 2. The method of claim 1 wherein the lattice is supported on a matrix of parallel, elongate segments of a topological superconductor, wherein the segments of each row of the matrix connect at each end to one of a plurality of semiconductor rails aligned perpendicular to the segments, and wherein a bridge of a non-topological superconductor bridges adjacent pairs of segments comprising a tetron. (Hastings’ fig. 3 shows the lattice of majorana “x”, where each rail “SC” is shown in a single and double-rail configuration, see below. The topological segments are labeled “Top” and the superconductor is labeled S-wave.)
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Chao teaches claim 3. The method of claim 1 wherein the plaquette is a first plaquette and the measurement circuit is a first measurement circuit, the method further comprising implementing a second measurement circuit of the surface code on an adjacent second plaquette of qubits of the Majorana-tetron lattice, the second measurement circuit corresponding to a stabilizer of the surface code, and comprising: (Chao sec. III “A round of stabilizer measurements produces an outcome bit for each plaquette, the so-called syndrome bits. “ Chao fig. 2 “Green and yellow plaquettes support respectively X-type and Z-type measurements.” “FIG. 7. Schedules for the joint Pauli measurements between data qubits and ancillas…” Chao expressly applies complementary x and z stabilizers circuits across neighboring plaquettes)
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distributing among the sequence of time steps a set of one-qubit projective-measurement loops
distributing among the sequence of time steps a set of two-qubit projective-measurement loops on each data qubit of the second plaquette
distributing among the sequence of time steps a set of two-qubit projective measurement loops (Chao fig. 7 shows that there are many plaquettes and that the plaquette measurement is a repeated step over several plaquettes. Chao fig. 6 “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements.” Chao fig. 7 “FIG. 7. Schedules for the joint Pauli measurements between data qubits and ancillas…”)
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Chao doesn’t teach the three ancilla.
However, Chamberland teaches on each of three auxiliary qubits of the second plaquette;… together with one of the three auxiliary qubits of the second plaquette; and… two or more auxiliary-qubit pairs selected from the three auxiliary qubits of the second plaquette. (Chamberland para 49 “performing measurements includes measuring an error in a quantum circuit using at least one ancilla qubit and at least two flag qubits, the quantum circuit comprising a sub-plurality of data qubits in the plurality of data qubits and a plurality of gates.” The claims don’t limit the scope to only “one of the three auxiliary qubits” or only one “auxiliary-qubit pairs”, therefore when Chamberland teaches using three ancilla qubits for the measurement of the data qubit, Chamberland teaches the broad scope of the claim element.)
Hastings teaches claim 6. The method of claim 2 wherein the lattice is a double-rail lattice, wherein each rail connects to one column of segments and is adjacent to another rail, which connects to an adjacent column of segments… (Hastings’ fig. 3 shows the lattice of majorana “x”, where each rail “SC” is shown in a single and double-rail configuration, see below. The topological segments are labeled “Top” and the superconductor is labeled S-wave.)
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Hastings doesn’t teach the timesteps.
However, Chao teaches wherein the sequence includes four repeating time steps. (Chao fig. 6 “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements.”)
Hastings teaches claim 7. The method of claim 2 wherein the lattice is a single-rail lattice, wherein each rail connects to segments of adjacent columns of the matrix, (Hastings’ fig. 3 shows the lattice of majorana “x”, where each rail “SC” is shown in a single and double-rail configuration, see below. The topological segments are labeled “Top” and the superconductor is labeled S-wave.)
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Hastings doesn’t teach the timesteps.
However, Chao teaches wherein the sequence includes five repeating time steps. (Chao fig. 6 “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements.”)
Chao teaches claim 8. The method of claim 2 further comprising distributing additional measurement loops for detecting a circuit-noise hook error, equivalent to an error on two of the data qubits. (Chao sec. IV p. 6 “one can choose the ordering of the CNOT gates so that the weight-two error just de scribed (an example of a hook error [2]) is orthogonal to the minimum-weight logical operators, thereby behaving effectively as a weight-one error for the purposes of error correction…”)
Hastings teaches claim 9. The method of claim 8 wherein the lattice is a double-rail lattice, wherein each rail connects to one column of segments and is adjacent to another rail, which connects to an adjacent column of segments, (Hastings’ fig. 3 shows the lattice of majorana “x”, where each rail “SC” is shown in a single and double-rail configuration, see below. The topological segments are labeled “Top” and the superconductor is labeled S-wave.)
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Hastings doesn’t teach the timesteps.
However, Chao teaches wherein the sequence includes seven repeating time steps. (Chao fig. 6 “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements.”)
Hastings teaches claim 10. The method of claim 8 wherein the lattice is a single-rail lattice, wherein each rail connects to segments of adjacent columns of the matrix (Hastings’ fig. 3 shows the lattice of majorana “x”, where each rail “SC” is shown in a single and double-rail configuration, see below. The topological segments are labeled “Top” and the superconductor is labeled S-wave.)
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Hastings doesn’t teach the timesteps.
However, Chao teaches and wherein the sequence includes eight repeating time steps. (Chao fig. 6 “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements.”)
Chao teaches claim 11. A quantum computer comprising:
a plurality of physical qubits arranged on a Majorana-(Hastings’ fig. 3 shows the lattice of majorana “x”, where each rail “SC” is shown in a single and double-rail configuration, see below. The topological segments are labeled “Top” and the superconductor is labeled S-wave.)
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an interface configured to enact a measurement circuit of a surface code on a plaquette of qubits of the qubit lattice, the measurement circuit corresponding to a stabilizer of the surface code, and configured to: (Chao abs “we present surface code error-correction schemes using only Pauli measurements on single qubits and on pairs of nearest-neighbor qubits.” Chao sec. 1 p. 1 “reliable measurements of qubit Pauli operators—which can be realized by gathering relevant constituent Majoranas…” Chao sec. III “The surface code [1–3] encodes one logical qubit into a grid of d × d physical qubits as shown in Fig. 2.”)
distribute among a sequence of time steps a set of one-qubit projective-measurement loops (Chao sec. IV “Here we consider how to implement the weight-four X⊗4 andZ⊗4 stabilizer measurements required for the surface code using measurement-based qubits.” Chao fig. 6, below, “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements.”)
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distribute among the sequence of time steps a set of two-qubit projective-measurement loops on each of four data qubits of the plaquette (Chao fig. 6 “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements.” Chao fig. 7 “FIG. 7. Schedules for the joint Pauli measurements between data qubits and ancillas…” Chao’s plaquette contains four data qubits.)
distributing among the sequence of time steps a set of two-qubit projective measurement loops
advance through each of the time steps of the sequence, executing the one- and two-qubit projective measurements distributed therein, (Chao fig. 6 “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements.” Chao fig. 6 show stepping through 16 time steps taking 10 single qubit measurements and 8 joint measurements.) such measurements generating measurement of a stabilizer operator of the surface code. (Chao fig. 6 “FIG.6. Measurement-based circuits which implement the X ⊗ 4 stabilizer measurement.”)
Chao doesn’t teach a tetron lattice.
However, Hastings teaches plaquette of qubits of a Majorana-tetron lattice (Hastings para 17 “mesoscopic superconducting islands that each host 4 Majorana zero modes (MZMs), a unit that is collectively referred to herein as a “Majorana Tetron qubit” (also known as a ‘Majorana Quad qubit”).”)
Hastings, Chao and the claims all measure Majoranas zero modes. It would have been obvious to a person having ordinary skill in the art, at the time of filing, to use a tetron lattice “Four is the smallest number of MZMs that supports a single computational qubit, which is encoded in the nonlocal (topological) state space of the MZMs…” Hastings para 17.
Chao doesn’t teach the number of auxiliary qubits.
However, Chamberland teaches on each of three auxiliary qubits of the plaquette,… together with one of the three auxiliary qubits,… on two or more auxiliary-qubit pairs selected from the three auxiliary qubits of the plaquette;… (Chamberland para 49 “performing measurements includes measuring an error in a quantum circuit using at least one ancilla qubit and at least two flag qubits, the quantum circuit comprising a sub-plurality of data qubits in the plurality of data qubits and a plurality of gates.” The claims don’t limit the scope to only “one of the three auxiliary qubits” or only one “auxiliary-qubit pairs”, therefore when Chamberland teaches using three ancilla qubits for the measurement of the data qubit, Chamberland teaches the broad scope of the claim element.)
Chamberland, Chao and the claims all have ancilla qubits to assist measuring data qubits. It would have been obvious to a person having ordinary skill in the art, at the time of filing, to distribute measurements among time steps of the data qubits together with at least three auxiliary qubits so that “the extra ancillas can also become resources for the decoding process.” Chamberland para 44.
Chao teaches claim 12. The quantum computer of claim 11 wherein the plaquette is a first plaquette and the measurement circuit is a first measurement circuit, the method further comprising enacting a second measurement circuit of the surface code on an adjacent second plaquette of qubits of the Majorana-tetron lattice, the second measurement circuit corresponding to a stabilizer of the surface code, and configured to: (Chao sec. III “A round of stabilizer measurements produces an outcome bit for each plaquette, the so-called syndrome bits. “ Chao fig. 2 “Green and yellow plaquettes support respectively X-type and Z-type measurements.” “FIG. 7. Schedules for the joint Pauli measurements between data qubits and ancillas…” Chao expressly applies complementary x and z stabilizers circuits across neighboring plaquettes)
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distribute among the sequence of time steps a set of one-qubit projective-measurement loops
distributing among the sequence of time steps a set of two-qubit projective-measurement loops on each data qubit of the second plaquette
distributing among the sequence of time steps a set of two-qubit projective measurement loops on two or more auxiliary-qubit pairs (Chao fig. 7 shows that there are many plaquettes and that the plaquette measurement is a repeated step over several plaquettes. Chao fig. 6 “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements.” Chao fig. 7 “FIG. 7. Schedules for the joint Pauli measurements between data qubits and ancillas…”)
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Chao doesn’t teach the three ancilla.
However, Chamberland teaches on each of three auxiliary qubits of the second plaquette;… together with one of the three auxiliary qubits of the second plaquette; and… two or more auxiliary-qubit pairs selected from the three auxiliary qubits of the second plaquette. (Chamberland para 49 “performing measurements includes measuring an error in a quantum circuit using at least one ancilla qubit and at least two flag qubits, the quantum circuit comprising a sub-plurality of data qubits in the plurality of data qubits and a plurality of gates.” The claims don’t limit the scope to only “one of the three auxiliary qubits” or only one “auxiliary-qubit pairs”, therefore when Chamberland teaches using three ancilla qubits for the measurement of the data qubit, Chamberland teaches the broad scope of the claim element.)
Hastings teaches claim 14. The quantum computer of claim 12 wherein the lattice is a double-rail lattice, wherein each rail connects to only column of segments of the matrix and is adjacent to another rail, which connects to an adjacent column of segments, (Hastings’ fig. 3 shows the lattice of majorana “x”, where each rail “SC” is shown in a single and double-rail configuration, see below. The topological segments are labeled “Top” and the superconductor is labeled S-wave.)
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Hastings doesn’t teach the timesteps.
However, Chao teaches and wherein the sequence includes four repeating time steps. (Chao fig. 6 “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements.”)
Hastings teaches claim 15. The quantum computer of claim 12 wherein the lattice is a single-rail lattice, wherein each rail connects to segments of adjacent columns of the matrix, (Hastings’ fig. 3 shows the lattice of majorana “x”, where each rail “SC” is shown in a single and double-rail configuration, see below. The topological segments are labeled “Top” and the superconductor is labeled S-wave.)
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Hastings doesn’t teach the timesteps.
However, Chao teaches wherein the sequence includes five repeating time steps. (Chao fig. 6 “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements.”)
Chao teaches claim 16. The quantum computer of claim 12 wherein the measurement circuit includes additional projective-measurement loops for detecting a circuit-noise hook error, equivalent to an error on two of the data qubits. (Chao sec. IV p. 6 “one can choose the ordering of the CNOT gates so that the weight-two error just described (an example of a hook error [2]) is orthogonal to the minimum-weight logical operators, thereby behaving effectively as a weight-one error for the purposes of error correction…”)
Hastings teaches claim 17. The quantum computer of claim 16 wherein the lattice is a double-rail lattice, wherein each rail connects to only column of segments of the matrix and is adjacent to another rail, which connects to an adjacent column of segments, (Hastings’ fig. 3 shows the lattice of majorana “x”, where each rail “SC” is shown in a single and double-rail configuration, see below. The topological segments are labeled “Top” and the superconductor is labeled S-wave.)
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Hastings doesn’t teach the timesteps.
However, Chao teaches wherein the sequence includes seven repeating time steps. (Chao fig. 6 “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements.”)
Hastings teaches claim 18. The quantum computer of claim 16 wherein the lattice is a single-rail lattice, wherein each rail connects to segments of adjacent columns of the matrix, (Hastings’ fig. 3 shows the lattice of majorana “x”, where each rail “SC” is shown in a single and double-rail configuration, see below. The topological segments are labeled “Top” and the superconductor is labeled S-wave.)
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Hastings doesn’t teach the timesteps.
However, Chao teaches wherein the sequence includes eight repeating time steps. (Chao fig. 6 “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements.”)
Chao teaches claim 19. A method for enacting complementary measurement circuits of a surface code on adjacent first and second plaquettes of qubits of a Majorana- (Chao sec. III “A round of stabilizer measurements produces an outcome bit for each plaquette, the so-called syndrome bits. “ Chao fig. 2 “Green and yellow plaquettes support respectively X-type and Z-type measurements.” “FIG. 7. Schedules for the joint Pauli measurements between data qubits and ancillas…” Chao expressly applies complementary x and z stabilizers circuits across neighboring plaquettes. Each plaquette gets the same measurement.)
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distributing among a sequence of time steps a set of one-qubit projective-measurement loops (Chao sec. III “A round of stabilizer measurements produces an outcome bit for each plaquette,…” Chao sec. IV “Here we consider how to implement the weight-four X⊗4 andZ⊗4 stabilizer measurements required for the surface code using measurement-based qubits.” Chao fig. 6, below, “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements.”)
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distributing among the sequence of time steps a set of two-qubit projective-measurement loops on each of four data qubits of the first plaquette (Chao sec. III “A round of stabilizer measurements produces an outcome bit for each plaquette…” Chao fig. 6 “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements.” Chao fig. 7 “FIG. 7. Schedules for the joint Pauli measurements between data qubits and ancillas…” Chao’s plaquette contains four data qubits.)
distributing among the sequence of time steps a set of two-qubit projective measurement loops (Chao sec. III “A round of stabilizer measurements produces an outcome bit for each plaquette,…” Chao fig. 6 “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements…. the two connected ancillas are used together for a single plaquette measurement” Chao fig. 7 “FIG. 7. Schedules for the joint Pauli measurements between data qubits and ancillas…”)
advancing through each of the time steps of the sequence, executing the one- and two-qubit projective measurements distributed therein, (Chao fig. 6 “It takes 10 timesteps, involving 5 single-qubit and 6 joint measurements.” Chao fig. 6 show stepping through 16 time steps taking 10 single qubit measurements and 8 joint measurements.) such measurements corresponding to Z-or X-type stabilizer operators. (Chao sec. III “A round of stabilizer measurements produces an outcome bit for each plaquette, the so-called syndrome bits. “ Chao fig. 2 “Green and yellow plaquettes support respectively X-type and Z-type measurements.” “FIG. 7. Schedules for the joint Pauli measurements between data qubits and ancillas…” Chao expressly applies complementary x and z stabilizers circuits across neighboring plaquettes)
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Chao doesn’t teach a tetron lattice.
However, Hastings teaches plaquette of qubits of a Majorana-tetron lattice (Hastings para 17 “mesoscopic superconducting islands that each host 4 Majorana zero modes (MZMs), a unit that is collectively referred to herein as a “Majorana Tetron qubit” (also known as a ‘Majorana Quad qubit”).”)
Hastings, Chao and the claims all measure Majoranas zero modes. It would have been obvious to a person having ordinary skill in the art, at the time of filing, to use a tetron lattice “Four is the smallest number of MZMs that supports a single computational qubit, which is encoded in the nonlocal (topological) state space of the MZMs…” Hastings para 17.
Chao doesn’t teach the number of auxiliary qubits.
However, Chamberland teaches on each of three auxiliary qubits of the first plaquette, and on each of three auxiliary qubits of the second plaquette;… together with one of the three auxiliary qubits of the first plaquette, …together with one of the three auxiliary qubits of the second plaquette;… on two or more auxiliary-qubit pairs selected from the three auxiliary qubits of the first plaquette and the three auxiliary qubits of the second plaquette… (Chamberland para 49 “performing measurements includes measuring an error in a quantum circuit using at least one ancilla qubit and at least two flag qubits, the quantum circuit comprising a sub-plurality of data qubits in the plurality of data qubits and a plurality of gates.” The claims don’t limit the scope to only “one of the three auxiliary qubits” or only one “auxiliary-qubit pairs”, therefore when Chamberland teaches using three ancilla qubits for the measurement of the data qubit, Chamberland teaches the broad scope of the claim element.)
Chamberland, Chao and the claims all have ancilla qubits to assist measuring data qubits. It would have been obvious to a person having ordinary skill in the art, at the time of filing, to distribute measurements among time steps of the data qubits together with at least three auxiliary qubits so that “the extra ancillas can also become resources for the decoding process.” Chamberland para 44.
Chao teaches claim 20. The method of claim 19 wherein the first plaquette is an X-type plaquette and the second plaquette type is a Z-type plaquette. (Chao fig. 2 “Green and yellow plaquettes support respectively X-type and Z-type measurements.”)
Conclusion
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/AUSTIN HICKS/Primary Examiner, Art Unit 2142
1 “We reported plateaus in the conductance at 2e2/h, which we interpreted as evidence for the presence of Majorana zero-modes. However, several inconsistencies were pointed out by Sergey Frolov and Vincent Mourik between the raw measurement data that was made available to them and the figures that were published in the paper. We therefore re-analysed all the existing raw data for our original measurements and rebuilt the original experimental set-up for a re-calibration of the conductance values. We established that the data in two of the figures (Fig. 2a and Extended Data Fig. 4b) had been unnecessarily corrected for charge jumps (corrections that were not mentioned explicitly in the paper), and that one of the figure axes was mislabelled (Fig. 4b). The new conductance calibration shifted the plateau values by 8 per cent, above 2e2/h, which affects all the figures1. When the data are replotted over the full parameter range, including ranges that were not made available earlier, points are outside the 2-sigma error bars. We can therefore no longer claim the observation of a quantized Majorana conductance, and wish to retract this Letter.” Zhang, H., Liu, CX., Gazibegovic, S. et al. Retraction Note: Quantized Majorana conductance. Nature 591, E30 (2021). https://doi.org/10.1038/s41586-021-03373-x
2 “Nayak tried to make the case that his team had created the world’s first “topological” qubit, a robust quantum analog of the 0-or-1 bit used in conventional computers. Doing so would require not only conjuring the Majorana quasiparticle—a long-sought mode of electron behavior— but also controlling multiple Majoranas to encode quantum information. Many audience members, however, weren’t sold. “I don’t think the data are convincing,” says Jelena Klinovaja, a physicist at the University of Basel who attended Nayak’s talk at the American Physical Society’s (APS’s) Global Physics Summit.” Furor over
Quantum computing claim heats up by Zavitsky, Science 1338 28 MARCH 2025 • VOL 387 ISSUE 6741
3 Applicant’s specification [00101] discloses "one-dimensional topological-qubit architecture uses a semiconductor-superconductor heterostructure where superconductivity, strong spin-orbit coupling, and magnetic fields cooperate to form a topological, superconducting state that supports Majorana zero modes (MZMs)…” Applicant likely does not possess this technology.
4 “ https://www.nist.gov/quantum-information-science/quantum-computing-explained
5 “Producing Majoranas in the laboratory is very hard. Experiments combine cutting-edge fields
such as nanotechnology, superconductivity, device engineering and materials science.” Quantum computing’s reproducibility crisis: Majorana fermions by Sergey Frolov, p. 350 | Nature | Vol 592 | 15 April 2021
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