In the invisible domains of faint radio frequency signals and atomic quantum states, one of the most critical national security challenges of the present day is being played out, rather than on visible battlefields. The United States’ Positioning, Navigation, and Timing (PNT) capabilities, which are the bedrock of precise geolocation, trajectory planning, and time synchronization in the military, civil, and commercial sectors, are increasingly at risk. The global backbone of PNT has been GPS, a U.S.-invented system, for decades. Nevertheless, the inherent vulnerabilities of the system have become increasingly evident as adversaries employ anti-satellite weapons, spoofing, and jamming to disrupt or destroy GPS satellites. The potential economic losses could exceed $1 billion per day if disruptions escalate, as these assaults already disrupt military operations and thousands of commercial flights on a daily basis.
Quantum sensors emerge as a compelling alternative in response to these increasing hazards. Quantum sensing devices offer unparalleled measurement precision, long-term accuracy, and dependable performance in contested environments by capitalizing on the immutable properties of atoms. Quantum sensors are capable of maintaining and even exceeding current PNT services, in contrast to GPS, which is dependent on feeble radio frequency signals that are susceptible to interference. Their applications are diverse, ranging from the synchronization of telecommunications networks, power infrastructures, and financial systems to the navigation of submarines, drones, and munitions. Nevertheless, the realization of this potential is contingent upon the ongoing development and implementation of quantum sensing technologies.
GPS satellites are currently powered by atomic clocks, the most advanced quantum technology. Next-generation atomic clocks are expected to provide even greater synchronization accuracy. In the interim, quantum accelerometers and gyroscopes provide precise measurements of rotation and velocity, which are essential for navigation in the absence of GPS signals. Quantum gravimeters and magnetometers can utilize the distinctive gravitational and magnetic fields of Earth to achieve covert positioning. Collectively, these technologies offer improved, resilient PNT capabilities that do not depend on external signals that are susceptible to vulnerability.
Many quantum sensors are still too fragile and bulky for extensive operational use, although promising prototypes have transitioned from laboratories to field tests. These devices must be hardened to safeguard delicate quantum states from severe conditions and continuous use on dynamic platforms to provide real-world value. Additionally, the integration and miniaturization of atomic, optical, and control subsystems into compact, rugged devices are critical for their deployment in military and commercial applications.
The United States is fortunate to have the world’s most advanced innovation ecosystem in quantum sensing. Federal quantum research and development funding was increased from $200 million to approximately $1 billion annually by the 2018 National Quantum Initiative Act (NQIA). This funding has stimulated innovations in various fields, including prototype development and fundamental science. Advanced prototypes and early commercial solutions are delivered by approximately 20 companies, ranging from startups to established defense contractors, while 44 percent of the world’s most-cited quantum sensing publications are produced by U.S. research institutions, which is the largest global share. The Defense Innovation Unit’s Transition of Quantum Sensors (TQS) program prioritizes rapid iteration and military demonstrations, thereby expediting the maturation of technology.
Nevertheless, significant obstacles persist beyond just technological challenges. Congress has yet to reauthorize critical NQIA R&D programs that expired in 2023, despite the Trump administration’s advocacy for U.S. quantum leadership. This poses a threat to the sustainability of quantum innovation in civilian agencies. Although the United States attracts the largest proportion of private capital in quantum technologies, approximately 80 percent of it is directed toward quantum computing, leaving only 9 percent for quantum sensing. Private investment is uneven. This imbalance emphasizes the importance of strong public support, which is achieved through federal expenditures and market signals, to motivate private sector participation in quantum PNT.
Despite the immediate relevance of quantum sensors to mitigate GPS vulnerabilities affecting warfighters, recent defense appropriations have exacerbated this imbalance by prioritizing quantum computing over sensing. Additionally, the quantum programs of the U.S. Department of Defense are devoid of a centralized authority or coordination mechanism that would optimize their impact. The primary objective of the PNT Oversight Council has been to modernize GPS, a process that is currently experiencing years of delays and multi-billion-dollar cost overruns, rather than incorporating alternative solutions such as quantum sensors.
Quantum sensor developers are left with a limited supply base for critical components, including atomic vapor cells and low-noise lasers, as a result of the inconsistent demand from government and industry. Progress is further restricted by the limited availability of advanced micro- and photonic manufacturing capabilities. Neglecting the shared supply chain between quantum sensing and quantum computing, which shares numerous underlying components, could potentially undermine U.S. leadership in the entire quantum technology sector.
In the interim, the People’s Republic of China, which is the closest quantum competitor to the United States, is swiftly increasing the volume and impact of its quantum sensing research. China has the potential to surpass the United States in the development and deployment of technology, as it is supported by a robust state strategy, tight civil-military integration, sustained financing, and a substantial manufacturing capacity. The U.S. must act decisively in light of the fact that Chinese quantum-equipped satellites have already been tested and there are plans for expanded deployments by 2025.
U.S. quantum sensing is at risk of stagnating in a “valley of death” unless explicit and targeted measures are taken to address these challenges. This will impede the development of resilient solutions to GPS vulnerabilities and undermine America’s quantum edge. The CNAS report by Constanza M. Vidal Bustamante delineates policy recommendations that are concentrated on four critical areas: prioritizing warfighter needs by integrating quantum sensors into military platforms; strengthening supply chains through investment in domestic manufacturing; expanding civilian applications to generate market demand; and sustaining R&D ecosystems by renewing the NQIA with increased funding and establishing DoD-wide coordination to expedite development and deployment.
Quantum sensors are a complementary, long-term strategic advantage that complements the U.S. Space Force’s GPS modernization initiatives, which are designed to reduce jamming by 2025. To achieve success, it is necessary to address funding imbalances, cultivate public-private partnerships, and counteract China’s systemic investments. Every dollar invested in quantum sensing enhances the resilience of PNT and fortifies the entire U.S. ecosystem for quantum technology, thereby enhancing America’s competitive advantage in the global quantum race, as Dr. Vidal Bustamante emphasizes.