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 § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 3, 6, 7, 10, 12-17, 24 and 29-32 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding claim 3, it is not clear to which physical entities the magnetic field is applied.
Regarding claim 6, it is unclear to which physical entity (e.g. a layer of a heterostructure) and to which property (material property) the compositions in claim 6 are referring.
Regarding claim 7, it is unclear how a respective configuration of the device is accomplished such that wavefunctions are localized at different depths of the quantum well layer. In addition, the relative orientation of the depth direction with respect to the quantum well layer is unclear.
Regarding claim 10, the interpretation of “promote” is unclear and the asymmetric arrangement of the two electrodes is unclear.
Regarding claim 12, it is unclear to which physical property the aspect ratio is referring.
Regarding claims 13 and 14, the terminology “long axis” and “short axis” is unclear.
Regarding claim 15, the terminology “maximum area” is unclear.
Regarding claim 16, the relative orientations of the X-axes and the Y-axes with respect to the plane of the quantum well layer are unclear.
Regarding claim 17, it is unclear how the largest rectangular region is determined.
Regarding claim 24, there is lack of antecedent basis for “the exchange interaction.”
Regarding claim 29, it pertains to a mere result to be achieved.
Regarding claim 30, it is unclear to which physical property of the quantum well layer the limitation “having a variation of composition” refers.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claim(s) 1-33 are rejected under 35 U.S.C. 102(a)(2) as being anticipated by Thomas et al. (hereinafter “Thomas”), US Pub. No. 2021/0036110.
Regarding claim 1, Thomas teaches a qubit device (fig. 1, quatum dot device 100), comprising: a quantum well structure configured to host a hole gas in a quantum well ([0028] quantum well stack 146, quantum well layer 152; figs. 37-39 and accompanying text); and a plurality of electrodes configured to allow the formation of a plurality of quantum dots in the hole gas and to allow encoding of a unit of quantum information in a plurality of hole spins hosted in the quantum dots ([0082, 0084]).
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 2-5, 10, 11, 18-21, 23-28, 31, and 32 are rejected under 35 U.S.C. 103 as being unpatentable over Thomas (see above), in view of Henrickx et al. (hereinafter “Hendrickx”), “A four-qubit germanium quantum processor, 09/2020” (provided by applicant).
Regarding claim 2, Thomas fails to explicitly teach wherein the unit of quantum information is encoded into singlet and triplet states of the hole spins hosted in the quantum dots.
However, in the same field of endeavor, Hendrickx teaches wherein the low disorder in the quantum well enabled the construction of large arrays of quantum dots and the realization of two-qubit logic using two singlet-triplet qubits (see the first paragraph on page 580, the left-hand column).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Thomas to include the feature of Hendrickx. As such, a person having ordinary skill in the art would appreciate the motivation for doing so would have been to provide quantum error correction.
Regarding claim 3, Hendrickx teaches wherein the encoding of the unit of quantum information includes implementing X-rotations on the Block sphere of the qubit using a g-factor difference between hole spins and an applied magnetic field (second paragraph on page 583, left-hand column; second paragraph on page 582).
Regarding claim 4, Hendrickx teaches wherein the applied magnetic field is below 100mT (the qubit device in principle allows for the application of different magnetic field strenths).
Regarding claim 5, Hendrickx teaches wherein the hole gas is a two-dimensional hole gas in a planar quantum well layer of a heterostructure of semiconductor layers; the plurality of quantum dots comprises a double quantum dot having a first quantum dot hosting a first hole participating in the encoding of the unit of quantum information and a second quantum dot hosting a second hole participating in the encoding of the unit of quantum information; and the plurality of electrodes comprises a first set of electrodes configured to form the first quantum dot and a second set of electrodes configured to form the second quantum dot (figs. 1a, 1b on page 581; quantum well layer + plurality of electrodes; second paragraph on page 582, left hand column teaches double quantum dot; fig. 1b the first qubit is underneath the plunger gate P1, and the second qubit is underneath the plunger gate P2).
Regarding claim 10, Hendrickx teaches wherein the first and second sets of electrodes are arranged asymmetrically relative to each other to promote the size, shape, orientation and/or hole occupancy of the first quantum dot being different from the size, shape, orientation and/or hole occupancy of the second quantum dot (figs. 1a, 1b on page 581).
Regarding claim 11, Hendrickx teaches wherein the asymmetric arrangement is such that the first quantum dot has a different shape to the second quantum dot when viewed perpendicularly to the plane of the quantum well layer (figs. 1a, 1b on page 481).
Regarding claim 18, Hendrickx teaches wherein the X-axis pair of the first set and the X-axis pair of the second set together comprise three electrodes extending parallel to the Y-axis, the three electrodes comprising an outer electrode of the first set, an outer electrode of the second set, and an intermediate electrode between the outer electrodes and shared between the two sets (fig. 1a on page 481, electrodes P1 to P4).
Regarding claim 19, Hendrickx teaches wherein the Y-axis pair of the first set comprises an electrode extending parallel to the Y- axis and positioned between the outer electrode of the first set and the shared intermediate electrode, and a cross electrode extending parallel to the X-axis; and the Y-axis pair of the second set comprises an electrode extending parallel to the Y-axis and positioned between the outer electrode of the second set and the shared intermediate electrode, and a cross electrode extending parallel to the X-axis (fig. 1a on page 481, electrodes P1 to P4, points S1 to S2).
Regarding claim 20, Hendrickx teaches wherein the cross electrode of the first set and the cross electrode of the second set are misaligned with respective to each other along the X-axis, preferably by being at different positions along the Y-axis and/or angled differently relative to the X-axis (fig. 1a on page 481, electrodes P1 to P4, points S1 to S2).
Regarding claim 21, Hendrickx teaches wherein the cross electrode of the first set and the cross electrode of the second set are spaced apart from each other parallel to the X-axis by a gap; and the gap is displaced along the X-axis by more than 5nm from a symmetric position relative to the shared intermediate electrode (fig. 1a on page 481, electrodes P1 to P4, points S1 to S2).
Regarding claim 23, Hendrickx teaches wherein the quantum well layer is sandwiched between two confinement layers (fig. 1b on page 481).
Regarding claim 24, Hendrickx teaches implementing Z-rotations on the Bloch sphere of the qubit using the exchange interaction (fig. 8, page 597).
Regarding claim 25, it is a method of claim 1 and is rejected on the same grounds presented above.
Regarding claim 26, Hendrickx teaches wherein the plurality of quantum dots comprises a double quantum dot having a first quantum dot hosting a first hole participating in the encoding of the unit of quantum information and a second quantum dot hosting a second hole participating in the encoding of the unit of quantum information (fig. 1a, page 581).
Regarding claim 27, Hendrickx teaches wherein the electrodes are controlled such that the size, shape, orientation, hole occupancy in the first quantum dot, localization of the wavefunction of the first hole and/or electric field experienced by the first hole is/are respectively different from the size, shape, orientation, hole occupancy in the second quantum dot, localization of the wavefunction of the second hole and/or electric field experienced by the second hole (fig. 1a, page 581).
Regarding claim 28, Hendrickx teaches tuning a g-factor difference, preferably to be a least 1, by adjusting at least one of the following: a difference in size of the first quantum dot relative to the second quantum dot; a difference in shape of the first quantum dot relative to the second quantum dot; a difference in orientation of a shape of the first quantum dot relative to the second quantum dot; a difference in hole occupancy in the first quantum dot compared to the second quantum dot; a difference in composition at a location of the center of mass of the wavefunction of the first hole compared to the second hole; and a difference in electric field experienced by the first hole compared to the second hole (fig. 1a, page 581 and accompanying text).
Regarding claim 31, Hendrickx teaches wherein: the electrodes are controlled to localize the wavefunctions of the first and second holes in a quantum well layer having a variation of composition as a function of position in the quantum well layer; and the localization of wavefunctions is such that a center of mass of the wavefunction of the first hole is at a first location in the quantum well layer, the center of mass of the wavefunction of the second hole is at a second location in the quantum well layer, and the quantum well layer has different compositions at the first and second locations (figs. 1a, 1b, page 481).
Regarding claim 32, Hendrickx teaches wherein the first and second locations are at different depths in the quantum well layer (fig. 1b, page 481).
Allowable Subject Matter
Claims 8, 9, 22, and 23 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. The following is a statement of reasons for the indication of allowable subject matter: None of the prior art, either singularly or in combination teaches the specific limitations taught in the dependent claims above.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Zou et al. (US Pub. No. 20210182724) teaches quantum operation of a quantum processor.
Wu (US Patent No. 9,126,829) teaches a singlet-triplet qubit device.
Taylor (US Pub. No. 20140050242) teaches a quantum dot in a quantum well structure.
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/KENNETH B LEE JR/Primary Examiner, Art Unit 2625