Guest Post by Sinan Utku, Bilkent University Law School (Ankara); J.D. (Columbia University Law School) and Ph.D. (Yale University, physics)
The field of quantum computing is poised to advance dramatically in the near future. If expected advances actually occur, many problems that classical computing technologies cannot feasibly solve may become tractable. Given that the field is on the verge of fast and important technological advancements in this field, it makes sense to consider the patenting strategies that will be needed to protect them.
This article discusses patent eligibility of quantum computing inventions under U.S. law in the context of a concrete example. As such, the article is intended for workers in the field and assumes elementary quantum computing knowledge.
Patent Eligibility
Patent eligibility is one of the basic substantive requirements to obtain a patent. Not all creative output can be patented. For example, a painting, or a design, is obviously not patentable and can be only protected using other types of intellectual property. More arguable issues of patent eligibility arise in connection with computer-implemented inventions. For example, most practitioners in most patent systems would probably agree that a methodology or computer program for controlling an apparatus in an industrially useful process should be eligible. On the other hand, they would likely agree that a methodology or computer program that is specified at the level of abstraction of the manipulation of data in accordance with an algorithm, with no nexus to any specific technological process, should not be patentable. For example, a computer program directed to conversion of units, e.g., from inches to centimeters, even if it satisfied the other requirements of patentability, such as novelty and non-obviousness, should not be patentable. Otherwise, activities in entirely different fields that require such conversions, from biotechnology to mechanical technologies to hi-tech, might be pre-empted wholescale by patents issuing with broad and wide-ranging scope. There is a vast spectrum of computer-implemented inventions that span the gap between these extremes in which the issue of eligibility is less clear.
In several decisions from 2010 to 2014, the U.S. Supreme Court articulated restrictions on subject-eligible matter that were more onerous than what most practitioners had previously understood to be the case based on the previous set of Supreme Court cases. See, e.g., Alice Corp. Pty. Ltd. v. CLS Bank Int’l, 573 U.S. 208 (2014) (“Alice”); Mayo Collaborative Servs. v. Prometheus Labs., Inc., 566 U.S. 66 (2012) (“Mayo”). In particular, under the more recent Mayo/Alice framework, the court first asks whether the claims are directed to a law of nature, natural phenomenon, or abstract idea. If the claims are so directed, the court then asks whether the claims embody an “inventive concept”—i.e., whether the claims contain “an element or combination of elements that is ‘sufficient to ensure that the patent in practice amounts to significantly more than a patent upon the ineligible concept itself.’”
Based on a large number of patent eligibility decisions from courts over the years, many practitioners believe the Mayo/Alice framework lacks precision and is fraught with uncertainty. It is useful to consider a couple of examples to illustrate what some practitioners think are counterintuitive outcomes of applying this test.
Claim Ineligible for Being Directed to a Natural Law
In American Axle, one of the claims in question was directed to a method of manufacturing a shaft assembly of a driveline system. Am. Axle & Mfg., Inc. v. Neapco Holdings LLC, 967 F.3d 1285 (Fed. Cir. 2020), reh’g en banc denied, 972 F.3d 1349 (Fed. Cir. 2020), cert. denied, 142 S. Ct. 2902 (2022) (“American Axle”). The invention intended to attenuate shell mode vibrations and bending mode vibrations of the shaft assembly. It accomplished this through the tuning of a liner using Hooke’s law, which mathematically relates the mass and/or stiffness of an object to the frequency with which that object oscillates. Once manufactured and so tuned, the liner would then be inserted into the shaft assembly to attenuate the relevant vibrations.
Many reasonable practitioners have argued that this was the sort of invention that accomplishes a useful technological outcome and so should have been found eligible for patenting. The court, however, ultimately found that it was not eligible. In particular, the court in step one of the Mayo/Alice framework found that the claim was directed to controlling the mass and stiffness of at least one liner to configure the liner to match, using Hooke’s law, the relevant frequencies in order to attenuate vibrations. The court further found that the claim was not limited to any particular way of achieving this result, but instead broadly covered all methods and structures for doing so. The court accordingly found in step one of the Mayo/Alice framework that the claim was directed to an ineligible natural law.
The court in step two found that the claim failed to include any inventive concept that would transform it into eligible subject matter. In particular, the court found that the claim’s failure to include any steps relating to the specific design of a liner for damping two different vibration modes simultaneously, as recited, meant that there was no such inventive concept. In conclusion, the court found this claim to be ineligible for patenting.
Claim Ineligible for Being Directed to an Abstract Idea
In Symantec, one claim at issue was directed to a virus screening method in which a network node received data from either a calling party or a called party in connection with a call that was routed between these two parties. Intellectual Ventures I LLC v. Symantec Corp., 838 F.3d 1307 (Fed. Cir. 2016), cert. denied, 137 S. Ct. 1376 (2017) (“Symantec”). The claim further recited detecting a virus in the data, and, in response, inhibiting communication of at least a part of the data. The specification explained that placing the virus detection processing at a location other than that of the calling party and the called party avoided a second party receiving the virus. Further, the virus could be detected without making any alteration to the computer of the party who might otherwise receive the virus. The specification also pointed out that the prior art method of screening for computer viruses at the location of a calling or called party required frequent updates of the database of viruses at the location of each network user; placing virus screening at a network node other than the location of calling and called parties clearly avoided this disadvantage. Many reasonable practitioners thought that the invention accomplished useful technological outcomes and should have been eligible for a patent.
In step 1 of the Mayo/Alice framework, the court found that the claim was directed to the well known concept of virus screening, which it stated was an abstract idea. The court in particular stated that performing virus screening was a long prevalent process in the field of computer technology and was routine and conventional. In its consideration of step two of the Mayo/Alice framework, the court did not find any redeeming non-conventional feature in the claim. In particular, it found that carrying out the abstract idea in the recited telephone network did not confer eligibility, because the telephone network merely functioned as a generic environment in which to carry out the well-known abstract idea. The court dismissed the invention’s benefit of eliminating reception of a virus by a second party, stating that this was conventional because it was achieved anytime a recipient screened an email for viruses and forwarded the email to a second recipient. The court found that the claim was not eligible for a patent.
Patent Eligibility of Quantum Computing Inventions
Quantum computing inventions come in a variety of forms. They include hardware and hardware-related inventions that are directed to components of a quantum computer or processes carried out by the hardware to carry out quantum processing. They also include software-related inventions that, e.g., implement a new quantum algorithm for achieving a useful end. Quantum computing inventions are often useful, contain a technological advance and in many cases include specific hardware components. However, as illustrated by the American Axle and Symantec cases, none of these properties are sufficient to confer patent eligibility.
It is useful to consider a specific example of a quantum computing invention to discuss the typical patent eligibility issues that may arise. The use of surface codes for implementing logical qubits is a good example, given that it is centered around an algorithm that is independent of any specific hardware. Of course, surface codes are well known and are discussed in many introductory quantum computing textbooks. Consequently, an invention directed to a surface code at that level of generality would fail to satisfy the novelty and non-obviousness requirements for patentability. However, because surface codes are well-known to many quantum computing practitioners, they are good vehicles for discussing and illustrating the patent eligibility requirement.
Implementing a Logical Qubit in a Surface Code
Surface codes are a promising class of quantum error correction codes that will likely be used in fault-tolerant quantum computing. In a surface code, many physical data qubits collectively encode a logical qubit in a nonlocal, topologically protected manner, making it robust against physical errors. The qubits are arranged on a surface lattice, such as a plane, in which data qubits are interleaved with ancilla (measurement) qubits. These measurement qubits interact with neighboring data qubits to perform stabilizer measurements, extracting error syndromes without collapsing the encoded logical state. The syndromes reveal the presence and locations of errors, which can then be inferred and corrected using classical decoding algorithms.
In particular, a quantum computer might carry out the following functionality to construct a logical qubit and maintain it without errors:
- configure a plurality of data qubits on a two-dimensional lattice structure;
- interleave ancilla qubits with the data qubits, an configure the ancilla qubits to measure stabilizers of neighboring data qubits;
- periodically perform stabilizer measurements on the ancilla qubits to detect errors in the data qubits;
- determine error syndromes based on the stabilizer measurement results; and
- apply corrective operations to the data qubits based on the error syndromes.
The patent eligibility of such an invention could be challenged based on at least two grounds. First, the invention is largely directed to an error correction scheme that involves redundant bits. This concept has been known and broadly used in communication and classical computational technologies for a long time. Accordingly, the invention might be found to be directed to the abstract idea of error correction using redundant bits. The likelihood of this happening will be greater if the invention is not particularized to a specific quantum computer hardware platform or set of components; generally, inclusion of hardware elements increases the likelihood that the invention will be found to be patent eligible. Finally, just based on the above description of the invention, there may not be a good argument based on step 2 of the Mayo/Alice framework that there are inventive elements that transform the invention into eligible subject matter despite its being directed to an abstract idea. The invention specified above arguably has a foundation in error correction concepts that have long been used in classical computing.
In response to a challenge to the patent eligibility of the invention based on abstractness, the patentee could argue that the surface code improves the quantum computer of the invention. Generally, showing that the invention improves an existing technological process, or improves the device that carries out the invention is helpful in demonstrating patent eligibility. Further, the patentee’s description of hardware elements for carrying out at least some of the processing of the invention might help in establishing patent eligibility.
Additionally, the invention in this example is broadly drawn to a “quantum computing system”. Generally, showing that the invention improves an existing technological process, or improves the device that carries out the invention, is helpful in demonstrating patent eligibility. The patentee could reasonably argue that that the surface code and the resultant logical qubit improves the functioning of quantum computing systems. The invention could be found patent eligible based on such arguments.
Conclusion
Quantum computing appears to be on the threshold of an explosive innovative stage that likely will yield result in usefully operational quantum computers. Patent protection of innovations in the hardware of these quantum computers as well as the algorithms running on them will be critical in ensuring robust growth and development of the industry. However, the uncertain state of patent eligibility law in the US is a barrier to protecting many of these inventions. There is patent reform legislation pending in Congress that would reform patent eligibility law in response to the ongoing unhappiness with the current state of the law. But given its current polarization and paralysis, it is not clear when Congress might act to reform patent eligibility law and whether it might do so in a way that is helpful to the patenting of quantum computing inventions. In the meantime, IP counsel and personnel at quantum computing companies during the patenting process should carefully consider both the evolving patent eligibility case law and aspects in their inventions that may help establish patent eligibility.
Nothing in this article should be construed as reflecting the official views, opinions, or positions of any organisation or institution with which the author is affiliated. The author writes in a personal capacity only.
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