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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 01/09/2026 has been entered.
Response to Amendment
Claims 4, 6, 11, 21-23, and 27-28 have been cancelled; and claims 1-3, 5, 7-10, 12-20, and 24-26 are currently pending.
Priority
Acknowledgment is made of applicant's claim for foreign priority under 35 U.S.C. 119(a)-(d).
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 1-2, 5, and 12-13 are rejected under 35 U.S.C. 103 as being unpatentable over Betz et al. (US 2016/0300155 A1, hereinafter “Betz”) in view of Schenkel et al. (US 2013/0087766 A1, hereinafter “Schenkel”).
In regards to claim 1, Betz discloses (See, for example, Figs. 3) a processing element for a quantum processing apparatus (See, for example Abstract), the processing element comprising:
a silicon substrate (See, for example, 16, See also Pars [0075], [0076]);
a dielectric material (7, See, for example, Par [0075]), wherein the silicon substrate and the dielectric material form an interface (interface between 7 and 16);
an electrode (121, 122) formed on the dielectric material (7) for isolating one or more electrons in the silicon substrate to form a quantum dot (171, 172, See, for example, Pars [0075]-[0078]);
a group IV atom having a nuclear spin located in the wavefunction of the one or more electrons, the nuclear spin of the group IV atom entangled with the one or more electrons (See, for example, Par [0101], naturally occurring 29Si atoms are inherently entangled with electrons in the quantum dots and are also inherently within the waveforms of the electrons in order to generate the disclosed differences in hyperfine fields of each quantum dot); and
a control arrangement for controlling a quantum property of the quantum dot and the nuclear spin to operate as a qubit (See, for example, Par [0079], “coupling between the dos 171, 172, can be controlled by a back-gate provided …”, See also, Pars [0159]-[0165], [0185]-[0195], [0202]-[0214], and [0259]-[0260]).
Betz is silent regarding the specific recitation of a control arrangement for controlling a quantum property of the quantum dot and the nuclear spin to operate as a qubit.
Schenkel while disclosing a scalable quantum computer teaches a control arrangement for controlling a quantum property of the quantum dot and the nuclear spin to operate as a qubit
(Controlling quantum dot: See Par [0009], this is structural teaching silicon substrate => buried oxide=> semiconductor (28Si) =>dielectric => top gate electrodes that electrostatically define and isolate electrodes in quantum dots.
Controlling Nuclear spin: See Par [0017], this teaches a two-step control chain:
The electrode- defined quantum dot traps an electron whose spin is controllable, and
The electron spin couples to the donor nuclear spin via hyperfine interaction.
The nuclear spin serves as quantum memory while the electron spin is the operational qubit interface.
Voltage-controlled exchange coupling between Qdot and nuclear spin: See Par [0020], this teaches that by varying the electrode voltage, the operator tunes how strongly the quantum dot electron “communicate” the donor electron (which in turn is hyperfine-coupled to the nuclear spin). Turning this coupling on and off is what enables two-qubit gate operations involving the nuclear spin.
Protecting the nuclear spin coherence: See Par [0023], which teaches active control of nuclear spin coherence by ionizing/de-ionizing the donor (via gate voltages), and the protocol for reading quantum information out of the nuclear spin back into the electron spin system).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to modify Betz by Schenkel because this help provide scalable inter-qubit coupling achieved through electrode-controlled Heisenberg exchange between adjacent quantum dots rather than direct donor-donor interaction.
In regards to claim 12, Betz discloses (See, for example, Figs. 3. 5 and 13) a method of operation of a plurality of quantum processing elements (See, Abstract), each quantum processing element comprising
a silicon substrate (16),
a dielectric material (7), wherein the silicon substrate (16) and the dielectric material (7) form an interface,
an electrode (121, 122) formed on the dielectric material (7) for isolating one or more electrons in the silicon substrate (16) to form a quantum dot (171, 172),
a group IV atom having a nuclear spin located in the wavefunction of the one or more electrons, the nuclear spin of the group IV atom entangled with the one or more electrons (See, for example, Par [0101], naturally occurring 29Si atoms are inherently entangled with electrons in the quantum dots and are also inherently within the waveforms of the electrons in order to generate the disclosed differences in hyperfine fields of each quantum dot), and
a control arrangement for controlling a quantum property of the quantum dot and the nuclear spin to operate the quantum dot and the nuclear spin as a qubit (See, for example, Par [0079], “coupling between the dos 171, 172, can be controlled by a back-gate provided …”, See also, Pars [0159]-[0165], [0185]-[0195], [0202]-[0214], and [0259]-[0260]),
the method comprising the step of:
applying a signal via the control arrangement to control a state of the qubit (See, for example, Par [0079], “coupling between the dos 171, 172, can be controlled by a back-gate provided …”, See also, Pars [0159]-[0165], [0185]-[0195], [0202]-[0214], and [0259]-[0260]).
Betz is silent regarding the specific recitation of a control arrangement for controlling a quantum property of the quantum dot and the nuclear spin to operate as a qubit.
Schenkel while disclosing a scalable quantum computer teaches a control arrangement for controlling a quantum property of the quantum dot and the nuclear spin to operate as a qubit
(Controlling quantum dot: See Par [0009], this is structural teaching silicon substrate => buried oxide=> semiconductor (28Si) =>dielectric => top gate electrodes that electrostatically define and isolate electrodes in quantum dots.
Controlling Nuclear spin: See Par [0017], this teaches a two-step control chain:
The electrode- defined quantum dot traps an electron whose spin is controllable, and
The electron spin couples to the donor nuclear spin via hyperfine interaction.
The nuclear spin serves as quantum memory while the electron spin is the operational qubit interface.
Voltage-controlled exchange coupling between Qdot and nuclear spin: See Par [0020], this teaches that by varying the electrode voltage, the operator tunes how strongly the quantum dot electron “communicate” the donor electron (which in turn is hyperfine-coupled to the nuclear spin). Turning this coupling on and off is what enables two-qubit gate operations involving the nuclear spin.
Protecting the nuclear spin coherence: See Par [0023], which teaches active control of nuclear spin coherence by ionizing/de-ionizing the donor (via gate voltages), and the protocol for reading quantum information out of the nuclear spin back into the electron spin system).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to modify Betz by Schenkel because this help provide scalable inter-qubit coupling achieved through electrode-controlled Heisenberg exchange between adjacent quantum dots rather than direct donor-donor interaction.
In regards to claim 2, Betz discloses (See, for example, Figs. 3, 5 and 13) the group IV atom is a silicon-29 (29Si) atom (See, for example, Par [0101]).
In regards to claim 5, Betz discloses (See, for example, Figs. 3, 5 and 13) the group IV atom is an isotope of a group IV element having nuclear spin (See, “…that differences in random
hyperfine fields on each point 171, 172 can be used due to the random positions of the 29Si atoms naturally occurring in silicon. This is due to the non-zero nuclear spins of this isotope S (29Si) = 1/2. These hyperfine fields exhibit random temporal fluctuations with Gaussian distribution with standard deviation BZ = 20 T. Alternatively, external
micromagnets may be used.”, Par [0101]).
In regards to claim 13, Betz discloses applying a signal via the control arrangement to store information in the qubit (See, for example, Pars [0007], [0008], [0079], [0159]-[0165], [0185]-[0197], [0202]-[0214], [0234]-[0240] and [0259]-[0260])
Claim 3 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Betz in view of Schenkel as applied to claim 1 above, and further in view of Lidar.
In regards to claims 3 and 7, Betz discloses all limitations of claim 1 above except that the silicon substrate is an isotopically enriched 29Si substrate comprising less than
or equal to 800ppm of 29Si atoms.
Lidar discloses (See, for example, Fig. 2) the silicon substrate is an isotopically enriched 29Si substrate comprising less than or equal to 800ppm of 29Si atoms (See, Par [0073], where US Patent No. 6472681, herein incorporated by reference in its entirety. The quantum computer 250 comprises a silicon semiconductor substrate 4 into which a one-dimensional array of donor atoms of phosphorous-31 (31 P) is introduced to produce an arrayed nuclear spintronic system with a large electron wave function at the nuclei of donor atoms 31 P. The substrate is selected from materials that do not have nuclear spins, i.e. 28Si, 30Si, or both. A Si02 insulating layer 7 is placed over the silicon substrate 4, on which the A-gate 8 and J-gate 10 are placed. The A-gate is over the 31P donor atoms, and the J gate is between the 31P donor atoms. Varying the voltage on the A-gate controls the strength of the hyperfine interaction between the donor electrons around the 31P donor atoms and the nuclear spins of the 31P donor atoms. Changing the voltage on the J-gate turns on and off electron-mediated coupling between nuclear spins of adjacent31P donor atoms. The quantum state of 250 is the direction of the nuclear spin of the 31P donor atom. An alternative to using 31P as a donor atom includes the use of 29Si, which is an example of a spin 1/2 particle (i.e. The silicon substrate is an isotopically enriched 28Si substrate)).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to modify Betz by Lidar because this would help implement the capability to perform many quantum logical operations in parallel.
In regards to claim 7, Betz discloses all limitations of claim 1 above except that the group IV atom is implanted in the silicon substrate.
Lidar discloses, in Par [0073] and Fig. 2, a quantum computer 250 from known art. (See U.S. Patent No. 6,472,681, herein incorporated by reference in its entirety). The quantum computer 250 comprises a silicon semiconductor substrate 4 into which a one-dimensional array of donor atoms of phosphorous-31 (31 P) is introduced to produce an arrayed nuclear spintronic system with a large electron wave function at the nuclei of donor atoms 31 P. The substrate is selected from materials that do not have nuclear spins, i.e. 28Si, 30Si, or both. A Si02 insulating layer 7 is placed over the silicon substrate 4, on which the A-gate 8 and J-gate 10 are placed. The A gate is over the 31P donor atoms, and the J-gate is between the 31P donor atoms. Varying the voltage on the A-gate controls the strength of the hyperfine interaction between the donor electrons around the 31P donor atoms and the nuclear spins of the 31P donor atoms. Changing the voltage on the J-gate turns on and off electron-mediated coupling between nuclear spins of
adjacent 31P donor atoms. The quantum state of 250 is the direction of the nuclear spin of the 31P donor atom. An alternative to using 31P as a donor atom includes the use of 29Si, which is an example of a spin 1/2 particle.
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to modify Betz by Lidar because this would help implement the capability to perform many quantum logical operations in parallel.
Claims 8-9 and 14-17 are rejected under 35 U.S.C. 103 as being unpatentable over Betz in view of Schenkel as applied to claims 1 and 12 above, and further in view of Kane (USPN 6472681 B1, hereinafter “Kane”).
In regards to claims 8 and 9, Betz discloses all limitations of claim1 above but silent about the quantum dot electron wavefunction diameter is less than around 50nm; and the quantum dot electron wavefunction diameter is less than or equal to 15nm.
Kane while disclosing a quantum computer teaches (See, for example, Col. 5 lines 59-67) the quantum dot electron wavefunction diameter is less than around 50nm (100-200Å = 10nm -20 nm); and the quantum dot electron wavefunction diameter is less than or equal to 15nm (10nm -20nm, See, Col. 5 lines 59-67).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to modify Betz by Kane because this would help implement the capability to perform many quantum logical operations in parallel.
In regards to claim 14, Betz discloses all limitations of claim 13 above except that storing information in the qubit comprises: applying the signal to store information in the electron spin of the quantum dot; and swapping this information from the electron spin to the nuclear spin of the group IV atom.
Kane discloses applying the signal to store information in the electron spin of the quantum dot; and swapping this information from the electron spin to the nuclear spin of the group IV atom (See, for example, Col. 1 line 39 thru Col. 2 line 17).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to modify Betz by Kane because this would help implement the capability to perform many quantum logical operations in parallel.
In regards to claim 15, Betz as modified above discloses transporting quantum information from a first processing element of the plurality of processing elements to a second processing element of the plurality of processing elements (Col. 4 lines 50-55, Kane).
In regards to claim 16, Betz as modified above discloses transporting information from the first processing element to the second processing element comprises:
swapping the quantum information from the nuclear spin of the group IV atom of the first processing element to the electron spin of the first processing element (See, for example, Col. 6 lines 56-67, Kane); and
transporting the electron spin from the first processing element to the quantum dot of the second processing element (Col. 4 lines 50-55, Kane);
causing the transported electron spin to entangle with the nuclear spin of the group IV atom of the second processing element (See, for example, Col. 5 lines 27-36, Kane); and
swapping the quantum information from the transported electron spin to the nuclear spin of the group IV atom of the second processing element (Col. 8 lines 18-34, Kane).
In regards to claim 17, Betz as modified above discloses the electron spin of the first processing element is transported to the quantum dot of the second processing element via spin shuttling or exchange mediated coupling between the quantum dots of the first and second processing elements (See, for example, Col. 1:57 thru Col. 2 line 17; Col. 4 lines 50-55, and Col. 5: lines 27-36, Kane).
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Betz in view of Schenkel as applied to claim 1 above, and further in view of Awschalom et al. (Awschalom et al. “Quantum Technologies with optically interfaced solid-state spins”, Nature Photonics 12, pp. 516-527 (2018), hereinafter “Awschalom”).
In regards to claim 10, Betz discloses all limitations of claim1 above except that the nuclear spin of the group IV atom is entangled with the electron of the quantum dot via a hyperfine interaction between 100KHz-1MHz.
Awschalom while disclosing quantum technologies teaches the nuclear spin of the group IV atom is entangled with the electron of the quantum dot via a hyperfine interaction between 100KHz-1MHz (See, for example, Page 517, “For samples with natural isotope abundance, strongly coupled nuclei typically occur within 1 nm from the electron and have hyperfine couplings from 300 KHz…”, right column, the first 10 lines))
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to modify Betz by Awschalom because this would help increase speeds for interfacing quantum memories and enable high-throughput multiplexed versions of entanglement protocols.
Allowable Subject Matter
Claims 18 is allowed over prior art of record.
The following is an examiner' s statement of reasons for allowance:
See applicant’s remarks filed on 4/10/2025, pp. 9-11.
Claims 19-20, and 24-26 are also allowed as being dependent of the allowed independent base claim.
Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.”
Response to Arguments
Applicant’s arguments with respect to claims 1 and 12 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Correspondence
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ERMIAS T WOLDEGEORGIS whose telephone number is (571)270-5350. The examiner can normally be reached on Monday-Friday 8 am - 5 pm E.S.T..
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Britt Hanley can be reached on 571-270-3042. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/ERMIAS T WOLDEGEORGIS/Primary Examiner, Art Unit 2893