International Business Machines Corporation

Patent Trials and Appeals Board

Sep 14, 2021

2021000266 (P.T.A.B. Sep. 14, 2021)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
16/115,828 08/29/2018 Ali Javadiabhari P201805390US01 9533
108686 7590 09/14/2021
IBM IPLAW (GLF)
c/o Garg Law Firm, PLLC
800 Bonaventure Way, suite 115
Sugar Land, TX 77479
EXAMINER
DOAN, NGHIA M
ART UNIT PAPER NUMBER
2851
NOTIFICATION DATE DELIVERY MODE
09/14/2021 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
dpandya@garglaw.com
garglaw@gmail.com
uspto@garglaw.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
_________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
__________

Ex parte ALI JAVADIABHARI,
JAY M. GAMBETTA, ANDREW W. CROSS,
LUCIANO BELLO, and MARCO PISTOIA
__________

Appeal 2021-000266
Application 16/115,828
Technology Center 2800
___________

Before ADRIENE LEPIANE HANLON, DONNA M. PRAISS, and
SHELDON M. McGEE, Administrative Patent Judges.

HANLON, Administrative Patent Judge.

DECISION ON APPEAL

A. STATEMENT OF THE CASE
The Appellant1 filed an appeal under 35 U.S.C. § 134(a) from an Examiner’s
decision finally rejecting claims 1–6 and 8–20. We have jurisdiction under
35 U.S.C. § 6(b).
We REVERSE.

1 “Appellant” refers to “applicant” as defined in 37 C.F.R. § 1.42. The Appellant
identifies the real party in interest as International Business Machines Corporation.
Appeal Brief dated June 24, 2020 (“Appeal Br.”), at 2.
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Representative claim 1 is reproduced below from the Claims Appendix to
the Appeal Brief. The claim limitation at issue is italicized.2
1. A method for design optimization of a quantum circuit,
comprising:
analyzing a first quantum circuit design based on at least one of
a set of design criteria, wherein the first quantum circuit design
comprises a set of quantum logic gates, and wherein a design criterion
in the set of design criteria comprises changing a size of a matrix of
transformations corresponding to a number of qubits employed in the
first quantum circuit design, wherein analyzing the first quantum
circuit design further comprises determining a first entanglement state
of a first qubit; and
modifying the first quantum circuit design into a transformed
quantum circuit design, the modifying causing the transformed
quantum circuit design to perform an operation implemented in the
first quantum circuit design with a changed matrix of transformations.
Appeal Br. 14.
The Examiner maintains the following grounds of rejection on appeal:
(1) claims 1–4, 8–16, 19, and 20 under 35 U.S.C. § 102(a)(1) as
anticipated by Williams;3 and
(2) claims 5, 6, 17, and 18 under 35 U.S.C. § 103 as unpatentable over
Williams in view of Mosca.4
B. DISCUSSION
The Examiner finds Williams discloses a method for design optimization of
a quantum circuit comprising, inter alia, the analyzing step recited in claim 1
“wherein analyzing the first quantum circuit design further comprises determining

2 The limitation at issue in claim 1 is also recited in independent claims 11 and 20.
See Appeal Br. 15, 17.
3 US 2006/0123363 A1 to Williams et al., published June 8, 2006 (“Williams”).
4 US 2018/0039903 A1 to Mosca et al., published February 8, 2018 (“Mosca”).
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a first entanglement state of a first qubit” (underlining omitted; italics added).
Final Act. 4–55 (citing Williams ¶¶ 97, 99, 125, 126; Williams Figs. 5A, 5B).
At the outset, it is necessary to interpret the terms “analyzing” and
“determining” in the claim limitation at issue. See In re Hiniker Co., 150 F.3d
1362, 1369 (Fed. Cir 1998) (“the name of the game is the claim”). The Examiner
finds that the terms “analyze,” “evaluate,” and “determine” are synonyms for the
term “compute” and then interprets the term “determining” in claim 1 to mean
“computing.” Ans. 5–6;6 see also Reply Br. 27 (contending that the “Examiner
appears to be first interpreting determining a first entanglement state of a first qubit
as computing a first entanglement state of a first qubit, then providing support in
the reference for this interpretation” (original emphasis omitted; italics added)).
The Appellant, however, argues that “[c]laim 1 does not recite ‘compute’”
and “when interpreting claim 1, synonyms for terms not present in the claim – such
as ‘compute’ . . . – should not be adopted.” Reply Br. 2.
The Appellant does not define the terms “analyzing” or “determining” in the
Specification and neither the Appellant nor the Examiner provides a definition for
either term on appeal. Nonetheless, the Appellant discloses that “an analysis pass
of an embodiment collects information about the quantum circuit.” Spec. ¶ 14
(emphasis added). More specifically, the Appellant discloses:
Analysis pass component 410 analyzes the input quantum
circuit and collects information, such as a number of quantum logic
gates, the types of quantum logic gates, the depth of the quantum
circuit, and the number of qubits. Analysis pass component 410
includes a set of analysis passes capable of being executed by pass
manager component 408. For example, analysis pass component 410

5 Final Office Action dated March 27, 2020.
6 Examiner’s Answer dated September 14, 2020.
7 Reply Brief dated October 8, 2020.
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analyzes a first quantum circuit design based on at least one of a set of
design criteria for a new quantum circuit design. The quantum circuit
design of an embodiment includes a set of quantum logic gates. A
design criterion of the set of design criteria of an embodiment
includes changing a size of a matrix of transformations corresponding
to a number of qubits employed in the quantum circuit design. Once
the analysis pass component 410 finishes an analysis pass on the
quantum circuit, the collected information is returned to the pass
manager component 408. The pass manager component 408 updates
information about the input quantum circuit design and stores the
information as an updated quantum circuit design.
Spec. ¶ 70 (emphasis added).
Based on the Appellant’s disclosure, we interpret the term “analyzing,” as
used in the claims on appeal, to mean “collecting information.”8 Our interpretation
is consistent with the ordinary meaning of the term “analyze.” See Definition of
“analyze,” dictionary.cambridge.org/us/dictionary/english/analyze (last visited
Sept. 9, 2021) (defining “analyze” as “to study or examine something in detail, in
order to discover more about it” (emphasis added)). Moreover, “determining a
first entanglement state of a first qubit” is part of the analyzing step recited in
claim 1. Appeal Br. 14 (emphasis added); see also Spec. ¶ 18 (disclosing that
“analyzing the first quantum circuit design determines a first entanglement state of
a first qubit” (emphasis added)). Thus, consistent with our interpretation of the
term “analyze,” we interpret the term “determine” to mean “to discover

8 See In re Morris, 127 F.3d 1048, 1054 (Fed. Cir. 1997) (During examination, “the
PTO applies to the verbiage of the proposed claims the broadest reasonable
meaning of the words in their ordinary usage as they would be understood by one
of ordinary skill in the art, taking into account whatever enlightenment by way of
definitions or otherwise that may be afforded by the written description contained
in the applicant’s specification.”).
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the facts . . . about something” (emphasis added).9 Definition of “determine,”
dictionary.cambridge.org/us/dictionary/english/determine (last visited Sept. 9,
2021) (defining “determine” as “to discover the facts or truth about something”).
Claim 1 recites, inter alia, the step of “analyzing a first quantum circuit
design . . . wherein analyzing the first quantum circuit design further comprises
determining a first entanglement state of a first qubit.” Appeal Br. 14 (emphasis
added). Based on our interpretation of the terms “analyzing” and “determine”
identified above, we interpret the claim limitation at issue to mean collecting
information about or discovering, not calculating, a first entanglement state of a
first qubit.10 See Reply Br. 3 (contending that “determining is part of an analysis
of a property of a quantum circuit design – in other words, a measurement
operation, not a computation” (original emphasis omitted; italics added)).
Next, we turn to the anticipation rejection on appeal. “To anticipate a claim,
a prior art reference must disclose every limitation of the claimed invention, either
explicitly or inherently.” In re Schreiber, 128 F.3d 1473, 1477 (Fed. Cir. 1997);
see also In re Oelrich, 666 F.2d 578, 581 (CCPA 1981) (“Inherency . . . may not
be established by probabilities or possibilities. The mere fact that a certain thing
may result from a given set of circumstances is not sufficient.” (quoting Hansgirg
v. Kemmer, 102 F.2d 212, 214 (CCPA 1939))).

9 In contrast to the terms “analyze” and “determine,” the term “compute” means
“to calculate an answer or amount by using a machine” (emphasis added).
Definition of “compute,” dictionary.cambridge.org/us/dictionary/english/compute
(last visited Sept. 9, 2021).
10 We note that the Specification does not disclose how an entanglement state of a
qubit is determined.
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To support the anticipation rejection on appeal, the Examiner relies on
paragraphs 125 and 126 of Williams which disclose a method of data entry. Final
Act. 5. Williams discloses, in relevant part:
(1) Step 1: Make the Bit String-Eigenstate Correspondence: Given a
string of 2n classical bits, place these in 1-to-1 correspondence with
the set of 2n n-bit eigenstates. . . .
(2) Step 2: Map Bits to Superposition[11] State: Construct an equally
weighted superposition that is peaked at only those eigenstates which
correspond to a “1” in the given bit string sequence (i.e. the classical
data). . . . In general, this will be an entangled state[12] of n quantum
bits that encodes a specific sequence of 2n classical bits. . . .
(3) Step 3: Compute Unitary Transformation Needed to Make this
Superposition State Starting From (Say) ǀ00 . . . 0> . . . .
(4) Step 4: Compute the Quantum Circuit that Implements this
Unitary Transformation . . . .
Williams ¶¶ 124–126, 128 (emphasis added).
The Examiner appears to rely on the combination of encoding step (2) and
computing steps (3) and (4) to illustrate an analysis of a first entanglement state of
a first qubit as recited in claim 1. Ans. 7.
The Appellant argues:
Williams encodes a string of 2ʺ classical bits into an entangled state of
n quantum bits, computes a unitary transformation needed to make the
entangled state, then computes a quantum circuit implementing the
unitary transformation. Thus, the known entangled state is the output
of the quantum circuit, rather than a result of analyzing the circuit. In
addition, because in Williams the entanglement state is encoded first,
then a design generated to result in the entanglement state, Williams

11 According to the Appellant, “[s]uperposition means that each qubit can represent
both a 1 and a 0 at the same time.” Spec. ¶ 6.
12 According to the Appellant, “[e]ntanglement means that qubits in a superposition
can be correlated with each other in a non-classical way; that is, the state of one
(whether it is a 1 or a 0 or both) can depend on the state of another.” Spec. ¶ 6.
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has no need to analyze a circuit to determine an entanglement state
that is already known.
Appeal Br. 11 (original emphasis omitted; italics added); see also Reply Br. 3.
As discussed above, we interpret the claim limitation at issue to mean
collecting information about, not calculating, a first entanglement state of a first
qubit. This portion of Williams, however, does not describe collecting information
about an existing entanglement state as recited in claim 1. Rather, as the Appellant
contends, Williams constructs an entangled state of n quantum bits that encodes a
specific sequence of 2n classical bits, computes a unitary transformation needed to
make the entangled state, and then computes a quantum circuit that implements the
unitary transformation. Williams ¶¶ 125, 126, 128; Appeal Br. 11.
The Examiner also relies on paragraphs 97 and 99 of Williams to support the
anticipation rejection on appeal. Final Act. 5. Williams discloses, in relevant part:
Permutation matrices are a special class of 4ⅹ4 unitary matrices
possessing a single 1 in each row and column. Of the 4!=24 possible
permutation matrices, 16 are maximally entangling operations and 8
are non-entangling operations. In FIGS. 5A and 5B, we show the
optimal quantum circuit for each maximally-entangling permutation
matrix. . . .
The optimal circuits in FIGS. 5A and 5B were found using a
numerical technique that incrementally explores circuit templates of
increasing complexity until the simplest sufficient template is found.
This is feasible for 2-qubit gates but not, in general for n-qubit gates,
due to the exponentially growing number of possible templates to try.
Similarly, the invention can compute optimal circuits for the
remaining 8 non-entangling operations as shown in FIG. 6. We first
compute the entangling power of the unitary operator. If this is zero
this suggests that the unitary operator is either a direct product of 1-
qubit gates or equivalent to a SWAP gate up to 1-qubit gates.
Williams ¶¶ 97–99 (emphasis added).
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Williams, in paragraphs 97–99, does not expressly describe collecting
information about a first entanglement state of a first qubit as recited in claim 1.
Nonetheless, the Examiner contends that the phrase “‘incrementally exploring
circuit templates’ [in paragraph 98 of Williams] . . . means analyzing . . . these
quantum circuits until the simplest/optimal quantum circuit is found” and “involves
the determination . . . of a first entanglement states [sic] of a first qubit associated
with the circuit templates” as recited in claim 1. Ans. 8 (emphasis added).
Williams’ Figures 5A and 5B illustrate an optimal quantum circuit for each
maximally-entangling permutation matrix referred to in paragraph 97 of Williams.
See Williams ¶ 23. Williams discloses that the optimal circuits “were found using
a numerical technique that incrementally explores circuit templates of increasing
complexity until the simplest sufficient template is found.” Williams ¶ 98
(emphasis added). Significantly, the Examiner does not explain whether the
numerical technique described in Williams collects information about an
entanglement state of a qubit as claimed or is merely a computation method. See
Reply Br. 4 (arguing that “Williams starts with a matrix known to be maximally-
entangling, then generates circuit templates of increasing complexity
implementing the matrix” (original emphasis omitted; italics added)). Therefore,
the Examiner has failed to show that paragraphs 97–99 of Williams describe the
claim limitation at issue.
In sum, the Examiner has not established, by a preponderance of the
evidence, that Williams either expressly or inherently describes an analyzing step
comprising “determining a first entanglement state of a first qubit” as recited in the
independent claims on appeal. See In re Oetiker, 977 F.2d 1443, 1445 (Fed. Cir.
1992) (the examiner bears the initial burden of presenting a prima facie case of
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unpatentability). Therefore, the anticipation rejection of claims 1–4, 8–16, 19, and
20 based on Williams is not sustained.
The Examiner’s reliance on Mosca does not cure the deficiencies in
Williams. Final Act. 7; see also Appeal Br. 12 (arguing that the “Examiner
combines Mosca with Williams only to allege teachings of specific features of
claims 5–6 and 17–18” (emphasis omitted)). Therefore, the obviousness rejection
of claims 5, 6, 17, and 18 based on the combination of Williams and Mosca also is
not sustained.
C. DECISION
The Examiner’s decision is reversed.
In summary:

Claims
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
1–4, 8–16,
19, 20
102(a)(1) Williams 1–4, 8–16,
19, 20
5, 6, 17, 18 103 Williams, Mosca 5, 6, 17, 18
Overall
Outcome
1–6, 8–20

REVERSED