IBM Corp v. Rigetti & Co Inc

1. Case Identification

• Case #: IPR2020-00494
• Patent #: 9,836,699
• Filed: January 31, 2020
• Petitioner(s): IBM Corporation
• Patent Owner(s): Rigetti & Company, Inc.
• Challenged Claims: 1, 7-13, 18-20, 22-28, 30, 38, 40-43

2. Patent Overview

• Title: Quantum Computing Apparatus with Interposer
• Brief Description: The ’699 patent discloses a quantum computing apparatus that includes a quantum circuit device and an interposer. The interposer serves to connect the quantum circuit device to external components, such as a control system, via a plurality of cables.

3. Grounds for Unpatentability

Ground 1: Obviousness over Schoelkopf, Matsuo, and Frunzio - Claims 1, 13, 19, 20, 22, 27, 28, and 38 are obvious over Schoelkopf in view of Matsuo and Frunzio.

• Prior Art Relied Upon: Schoelkopf (WO 2014163728), Matsuo (Patent 6,614,106), and Frunzio (a June 2005 IEEE article).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Schoelkopf disclosed the foundational quantum computing apparatus, including a quantum circuit device (substrates with qubits) and a multi-layer interposer for connecting to an external coaxial line. However, Schoelkopf did not detail how to implement signal processing circuitry within its interposer. Petitioner contended that Matsuo supplied this missing element by teaching an interposer containing various circuit elements for signal processing. The combination of Schoelkopf and Matsuo thus rendered obvious an apparatus with an interposer comprising an intermediate layer with an integrated circuit layer. Furthermore, while Schoelkopf taught connecting to coaxial lines, Frunzio explicitly taught using a plurality of coaxial terminals and cables for communicating with a superconducting qubit device, rendering obvious the claimed plurality of terminals and cables.
  • Motivation to Combine: A POSITA would combine Schoelkopf and Matsuo to improve Schoelkopf’s device by integrating necessary signal processing circuits directly into the interposer, which is more compact and efficient for handling weak qubit signals before they are attenuated. A POSITA would then incorporate Frunzio’s teachings for implementing the coaxial connections, as Schoelkopf itself suggested using connections "as known in the art." Frunzio provided a known, suitable implementation that facilitates scaling to the larger number of qubits envisioned by Schoelkopf.
  • Expectation of Success: Petitioner asserted a high expectation of success because the combination involved applying known techniques (Matsuo’s circuit-in-interposer, Frunzio’s coaxial connections) to a known quantum device architecture (Schoelkopf) to achieve the predictable result of a scalable, integrated quantum computing apparatus.

Ground 2: Obviousness over Schoelkopf, Matsuo, Frunzio, and Abdo - Claims 7, 8, and 10 are obvious over the combination of Ground 1 in view of Abdo.

• Prior Art Relied Upon: Schoelkopf (WO 2014163728), Matsuo (Patent 6,614,106), Frunzio (a June 2005 IEEE article), and Abdo (a 2014 Applied Physics Letters article).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground built upon the base combination of Ground 1, which established an interposer with an integrated circuit layer. Petitioner argued that Abdo taught specific, essential components for that circuit layer. Abdo disclosed that measuring weak qubit signals requires a "high-gain, low-noise chain of amplifiers" and provided an on-chip Josephson Directional Amplifier (JDA) to serve as the claimed quantum amplifier circuit (claim 8) and isolator circuit (claim 10). Abdo also taught using a directional coupling circuit (claim 7) in conjunction with the amplifier.
  • Motivation to Combine: A POSITA, tasked with designing the integrated circuit layer taught by Matsuo, would be motivated to include well-known and necessary components for qubit readout, as taught by Abdo. Abdo’s amplifier and coupler would predictably improve the signal-to-noise ratio, provide signal isolation, and enable proper biasing, all of which are beneficial for the efficient measurement goal of Schoelkopf's device.
  • Expectation of Success: Abdo stated that its components could be implemented "on the same chip....using standard microwave technology and fabrication processes," providing a strong basis for an expectation of success in integrating them into the interposer of the primary combination.

• Additional Grounds: Petitioner asserted additional obviousness challenges, arguing that claims were obvious over the Schoelkopf/Matsuo/Frunzio combination in further view of:

  • Schmitt (a 2014 Physical Review A article): For teaching a multiplexing circuit (claim 9) to address the challenge of reading out a large number of qubits.
  • Dotsenko (Patent 8,937,255): For teaching specific flip-chip bonding methods using metallic bumps and epoxy (claims 11, 12, 18, 30, 40, and 42).
  • Thom (Patent 9,231,181): For teaching the use of printed circuit boards (PCBs) and wire bonding as the interposer material and connection method (claims 23-26, 41, and 43).

4. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under 35 U.S.C. § 325(d) would be inappropriate. Although a related Schoelkopf reference was before the examiner during prosecution, it was never applied in any rejection, and the examiner issued a first-action allowance. Critically, Petitioner contended that the asserted combinations—Schoelkopf with Matsuo, Frunzio, and the other secondary references—were never considered, are not cumulative, and present new unpatentability arguments warranting review.

5. Relief Requested

• Petitioner requests the institution of an inter partes review and the cancellation of claims 1, 7-13, 18-20, 22-28, 30, 38, and 40-43 of the ’699 patent as unpatentable under 35 U.S.C. §103.