Publication Details

5 November 2024

Introduction

Quantum technology has transformative potential. Many scientists, technologists, CEOs and political leaders predict that quantum technology will revolutionize many aspects of our economic and social world. Senior national security officials and military leaders increasingly see great defence applications derived from harnessing this emerging field of physics and engineering. The technology readiness level (TRL) of many (if not most) quantum technologies remains low. This mean that much of quantum technology’s impact will be felt—if predictions about its latent potential turn out to be well placed—some way into the future. As Niels Bohr, the Danish physicist who made a foundation contribution to quantum theory, once quipped, “predictions can be very difficult, especially about the future.”[1] It is nonetheless prudent now to survey the ways in which quantum technologies will likely shape future defence affairs and national security more broadly.

Although largely in its infancy, much quantum technology is maturing—and rapidly so in some areas. Recent developments in the field have gained a lot of attention in recent years. Indeed, progress in quantum computing threatens to the disrupt current methods of cryptography, which is the process of hiding or coding information so that only the person a message was intended for can read it.

Much recent thinking in national security circles about quantum technology focuses on the implications of quantum-enabled codebreaking.[2] There are good reasons for this. Digital computers codebreaking a private key that protects an encrypted private communication, for example, could take longer than the lifetime of our universe. Hypothetically, a quantum computer could do this in minutes. Less attention is showered, however, on other and broader potential applications of quantum technology for defence. To address this imbalance, this INSIGHTS homes in on three prospective technology areas that will likely shape the future defence scene. These are sensing, communications, and computing. Each of these broad technology areas that spring from quantum mechanics will be examined for the most significant military applications to which they can be used. 

Before moving onto these three analytical sections, it is important to clarify what is meant here by quantum technology. In short, quantum technology refers to the application of quantum mechanics to a given field of technology.[3] Quantum mechanics is the mathematics that describes and predicts the behavior (actions and interactions) of atoms and the sub-atomic particles inside them. [4] These tiny particles often behave quite differently to larger objects. The phenomenon of superposition, for example, describes how a single quantum particle can be said to be in two places at the same time. Also, when two subatomic particles become entangled (i.e., entanglement), they can remain connected even when physically separated by a large distance.[5] As this commentary goes on to detail, a relatively recent maturing of quantum technologies—that largely exploit the quantum effects of entanglement and superposition—has the potential to shape defence affairs in profound ways.

Quantum technology’s defence applications

Sensing

Quantum computing usually gets everyone’s attention, but quantum sensors are advancing faster and will most likely be deployed sooner. Quantum-enabled systems can sense at levels unachievable by classical (and even AI-enhanced) systems. Exploiting qubits’ extreme sensitivity to disturbances, quantum sensors can measure tiny differences in all kinds of different properties like temperature, acceleration, gravity or time.[6] Quantum sensors promise to reach unprecedented sensitivity and precision in sensing various quantities such as, inter alia, electric and magnetic fields, vibrations, motion, and temperature. Advances in quantum sensors, for example, could provide alternative positioning, navigation, and timing (PNT) options, allowing military systems to operate in GPS-denied environments.

Working through the properties of entanglement, a quantum radar could generate billions of “entangled” photon pairs. In simple terms, one photon from each pair would be sent into the search area while the other was retained. “Signal” photons reflected to the sensor would then be compared to their “idler” mates, revealing information about objects detected.[7] Such a radar might be able to detect stealthy aircraft with fidelity and distinguish legitimate radar targets from decoys. Moreover, these radars would be largely immune to jamming and even detection by an adversary.

The successful development and deployment of a magnetometer based on a superconducting quantum interference device, or SQUID, for example, would revolutionize submarine detection.[8] Though, such superconducting magnetometers are exquisitely sensitive, and their promise has hitherto been limited to the lab.

While quantum radars hold enormous hypothetical potential, recent research questions the feasibility of ground-based microwave quantum radars.[9] The idea of space-based quantum-enabled light detection and ranging (LiDAR), however, looks more promising in the near term.[10]

Communications

Advanced quantum computers will be able to break most of the currently used asymmetric cryptographical schemes. It is not all bad news, however. Quantum communications, which refers to quantum information exchange via a quantum network that uses optical fiber or free-space channels, could protect against this threat. In addition, researchers have investigated establishing quantum communications links through water.[11] Such work could lead to secure quantum communications between submarines and surface vessels, and with other submarines, aircraft, or even satellites.

Quantum cryptography leverages the properties of particles to make messages essentially unhackable. Qubits (quantum bits that are the basic unit of information used to encode data in quantum computing) are incredibly sensitive; attempts to disrupt or even just observe them will force qubits to collapse. If an outside observer tries to intercept or monitor QKD (Quantum Key Distribution) protected communications, this will be detected by the message recipient.

Given the exponential increases in the data that must be acquired and analyzed to support timely decision-making in future operating environments, advanced militaries will rely ever more heavily upon a secure digital communication infrastructure. [12] Quantum communications could be a breakthrough technology to achieve this.

Computing

Furthermore, quantum computing will advance the use of QKD that could protect sensitive encrypted communications against hostile interception and protect long-term held data from future quantum computer attacks. QKD allows the creation of encryption keys that are encoded and transmitted using qubits, making them more difficult to break.

In addition to its impact on cryptography, quantum computers could bring about major advances in machine learning, spurring improved pattern recognition and machine-based target identification.[13] This could radically accelerate the fielding by some nations of autonomous weapon systems, leading to increased calls for stronger arms control measures.[14]

Quantum computers could enhance simulations that demonstrate military deployments, possible strategies, and other scenarios.[15] Furthermore, the multiplication of computing power enabled by quantum architectures could allow systems (crewed or uncrewed) to calculate geographical positioning without GPS using quantum gravimeters and inertial navigation systems. This would solve one of the main challenges for uncrewed undersea vehicles: the need to rise to periscope level at regular intervals to confirm location.[16]

Pursuing quantum supremacy

The pursuit of leadership in quantum technology may be the most important techno-security races of the first half of the twenty-first century.[17] Those states that are able to make a leap forward in this area may accrue significant national security benefits, especially in the field of cryptography. Those able to find pathways for the technology from the lab to the battlefield they may also give their militaries significant advantages in being able to detect adversaries through quantum sensing and by being able to operate in GPS-denied environments because of quantum-enabled positioning. Moreover, the potential computing power generated by a scalable quantum computer could lead to radical advances across a range of industries and accelerate the growing cognitive capabilities of artificial intelligence. This would, for example, have significant implications for what future autonomous military robots are able to accomplish on the battlefield and lead to a bouleversement in cyberwarfare. Failure to keep up with leaders in quantum technology will put those falling behind at a serious strategic disadvantage. Once left behind, there may be little hope of catching up with quantum leaders or offsetting their advantages through other niche technology areas.

Reflecting this emerging techno-security race, quantum technology is attracting increasing sums of government and commercial money. Beijing shows every intention of wanting to win this techno-security race. President Xi Jinping held a group study session of the Chinese Communist Party Politburo dedicated to quantum science, in which he stated that “developing quantum science and technology is of great scientific and strategic significance.”[18] China has launched two different satellites that are capable of quantum communication from outer space, which includes quantum teleportation of individual particles mediated by satellite communication. No other country is known to have launched quantum communication satellites.[19] The U.S. shows no intention of giving up its bid for quantum leadership. As early as 2018, the U.S. government produced a public national strategy for quantum science.[20] Apart from some sub-fields of quantum communications, experts assess that the U.S. is at the true forefront of innovation in the field.[21]

Because the field of quantum technology is still very nascent, it is problematic to discuss which country is currently “ahead.” By most relevant metrics, the United States and China are clearly the two leading nations in quantum science and technology. Other advanced middle powers, however, such as Canada are also seeking to leverage their scientific prowess in this area for economic and defence benefits.[22] It would be too reductionist to call this a U.S.-China quantum race akin to the Cold War space race between the then superpowers.

Conclusion

Many quantum defence applications discussed in this INSIGHTS are still theoretical due to the engineering challenges associated with implementation. Quantum sensing is the technology that is closest to useful deployment. U.S. and allied navies tested quantum gravimeters and inertial navigation systems during the 2022 Rim of the Pacific (RIMPAC) naval exercises.[23] For the realization of practical quantum computers, in contrast, many challenges remain, such as scalability and cost. Based on IBM roadmaps we could expect scalable quantum computers that can solve relevant problems within the next 20–30 years.[24]

Some experts claim that quantum technology has a hype problem.[25] That is, there are excessive expectations about quantum technology’s near-term impact that outpace the reality of what is achievable. Few in the field doubt the revolutionary potential of quantum technology, but there remain high technical hurdles to overcome.[26] Significant advances in physics and materials science are needed, for example, to produce the kind of game-changing quantum computers that theoreticians believe are possible. Overcoming these challenges and bringing quantum technology out of the laboratory into the real world would confer huge first-mover advantages to whoever accomplishes this. Not least, quantum leadership would generate significant benefits in defence affairs. Selecting emerging technologies to develop is often a high-stakes gamble, but quantum technology is clearly a risk worth taking.

[1] Taken from Michael Fitzsimmons, “The Problem of Uncertainty in Strategic Planning,” Survival 48, no. 4 (winter 2006-2007), 131.

[2] Michal Krelina, “Quantum Technology for Military Applications,” EPJ Quantum Technology, 6 November 2021, https://epjquantumtechnology.springeropen.com/articles/10.1140/epjqt/s40507-021-00113- y#citeas.

[3] James A. Lewis and Georgia Wood, Quantum Technology: Applications and Implications (Washington, D.C.: CSIS, May 2023), https://www.csis.org/analysis/quantum-technology-applications-and-implications/

[4] Jun John Sakurai, Modern Quantum Mechanics, 3^rd Edition (Cambridge, U.K.: Cambridge University Press, 2022).

[5] Emma Hankins, “What is Quantum technology and why should policymakers care about it?” Oxford Insights, 31 August 2023, https://oxfordinsights.com/insights/what-is-quantum-technology-and-why-should-policymakers-care-about-it/.

[6] Michiel van Amerongen, “Quantum Technologies in Defence and Security,” NATO Review, 3 June 2021, https://www.nato.int/docu/review/articles/2021/06/03/quantum-technologies-in-defence-security/index.html.

[7] Chris Jay Hoofnagle and Simon Garfinkel, “Quantum Sensors—Unlike Quantum Computers—Are Already Here,” Defense One, 27 June 2022, https://www.defenseone.com/ideas/2022/06/quantum-sensorsunlike-quantum-computersare-already-here/368634/.

[8] David Hambling, “China’s quantum submarine detector could seal South China Sea,” New Scientist, 22 August 2017, https://www.newscientist.com/article/2144721-chinas-quantum-submarine-detector-could-seal-south-china-sea/.

[9] Fred Daum, “Quantum Radar Cost and Practical Issues,” IEEE Aerospace Electronic Systems Magazine, 35(11) (2020), 8-20.

[10] D.C. Koblick, S. Wilkinson, Space-based spooky radar orbit determination benefits at Earth-Moon Lagrange points, in: AMOS 2020, 2020, p. 13.

[11] Mario Mastriani, Sundaraja Sitharama Iyengar, and K. J. Latesh Kumar, “Bidirectional teleportation for underwater quantum communications,” Quantum Information Processing 20, no. 1 (2021).

[12] US DoD, Summary of the Joint All-Domain Command & Control Strategy, March 2022, https://media.defense.gov/2022/Mar/17/2002958406/-1/-1/1/SUMMARY-OF-THE-JOINT-ALL-DOMAIN-COMMAND-AND-CONTROL-STRATEGY.PDF.

[13] Kelley M. Sayler, “Defense Primer: Quantum Technology,” Congressional Research Service, updated 25 October 2023, https://crsreports.congress.gov/product/pdf/IF/IF11836.

[14] Ash Rossiter and Peter Layton, Warfare in the Robotics Age (Boulder, Co: Lynne Rienner, 2024).

[15] Ajey Lele, Quantum Technologies and Military Strategy (Springer, 2021).

[16] Martino Travagnin, Cold Atom Interferometry for Inertial Navigation Sensors (Technology Assessment: Space and Defence Applications, Luxembourg, Publications Office of the European Union, 2020), p. 15, https://data.europa.eu/doi/10.2760/237221.

[17] Tai Ming Cheung and Thomas G. Mahnken, “The Great Race for Techno-Security Leadership,” War on the Rocks, 31 August 2022, https://warontherocks.com/2022/08/the-grand-race-for-techno-security-leadership/.

[18] Zhang Zhihao, “Xi Highlights Crucial Role of Quantum Tech,” China Daily, 19 October 2020.

[19] Ryan Lovelace, “Boldly going: China’s teleportation prowess comes under congressional panel’s scrutiny,” Washington Times, 6 February 2024.

[20] U.S. Subcommittee on Quantum Information Science, Committee on Science, National Science and Technology Council, “National Strategic Overview for Quantum Information Science,” September 2018.

[21] Testimony presented before the U.S.-China Economic and Security Review Commission at the hearing “Current and Emerging Technologies in U.S.-China Economic and National Security Competition” on 1 February 2024, https://www.uscc.gov/sites/default/files/2024-02/Edward_Parker_Testimony.pdf.

[22] Ash Rossiter, Leveraging Quantum Technology for Canadian Defence (Calgary, Canada: Canadian Global Affairs Institute, September 2024), https://www.cgai.ca/leveraging_quantum_technology_for_c

anadian_defence.

[23] U.S. Subcommittee on Quantum Information Science, Committee on Science, National Science and Technology Council, National Quantum Initiative Supplement to the President’s FY 2024 Budget, December 2023.

[24] Joran van Apeldoorn and Koen Groenland, “The Professional’s Guide to Quantum Technology,” Quantum Amsterdam, accessed 8 May 2023; and “McKinsey Technology Trends Outlook 2022,” McKinsey & Company, August 2022.

[25] Sankar Das Sarma, “Quantum Computing Has a Hype Problem,” MIT Technology Review, 28 March 2022, https://www.technologyreview.com/2022/03/28/1048355/quantum-computing-has-a-hype-problem/.

[26] Ash Rossiter, “Hyping Emerging Military Technology: Probing the Causes of Consequences of Excessive Expectations,” International Relations, published online 17 July 2023.