Quantum sensors have revolutionized measurement science by offering unprecedented precision and sensitivity. These sensors exploit quantum phenomena to detect minute signals that are often imperceptible to classical devices. Now, the frontier of this technology is being pushed even further by exploiting quantum entanglement—a phenomenon that connects particles regardless of the distance between them. The University of Michigan is spearheading a groundbreaking $9 million initiative funded by the U.S. Office of Naval Research, aimed at developing entangled networks of quantum sensors that promise to redefine measurement fidelity and networking capabilities.
Entanglement essentially binds particles through their quantum states, enabling instant correlations between them. When one particle is measured, the other’s state is instantaneously affected, no matter how far apart they are. This property offers a promising avenue for networks involving quantum sensors, where entanglement could heighten measurement sensitivity beyond the classical limits imposed by unentangled sensor arrays. According to Zheshen Zhang, associate professor of electrical and computer engineering at U-M and project lead, entanglement not only enhances the resolution of distributed sensor networks but also accelerates data acquisition, boosting the signal-to-noise ratio significantly over conventional configurations.
The vision extending from this multidisciplinary project is to integrate quantum sensing within the wider framework of emerging quantum technologies, such as quantum computing and quantum networking. By doing so, the team anticipates revolutionizing sensor performance through optimized quantum resource management. Their work is anticipated to transition quantum sensors from isolated devices to interconnected networks that leverage entanglement for enhanced capabilities, foreshadowing a new era in precision measurement and sensing technology.
Traditionally, quantum sensors have been connected using classical communication channels like fiber optics, but the advent of entanglement-enabled networking offers a fundamentally new paradigm. The crux of the research is quantifying the precision gains attainable through entangled sensor networks beyond what classical networking can achieve. Such advancements have the potential to impact a wide array of technologies, including but not limited to, the enhancement of atomic clocks, the precision of autonomous navigation systems free from GPS constraints, and the heightened detection of magnetic and radiofrequency fields critical for various scientific and defense applications.
However, translating the theoretical advantages of entangled sensor networks into practical technology faces significant challenges, particularly in maintaining entanglement over extended periods and distances. Environmental noise and quantum decoherence threaten to sever the delicate quantum correlations between sensors. Thus, the research effort also focuses on developing robust error suppression and correction methodologies that will sustain entanglement integrity in real-world conditions, paving the way for operational quantum sensing networks.
The project employs two distinct experimental platforms as testbeds to demonstrate and refine their quantum networking strategies. The first platform uses arrays of Rydberg atoms, extraordinary atoms with electrons excited to very high-energy states, causing their electron orbitals to swell significantly. These atoms are exceptionally sensitive to variations in electric and magnetic fields owing to their amplified electronic extent. What’s extraordinary within this system is the ability to create a quantum superposition state involving pairs of Rydberg atoms. Contrary to classical expectations, two neighboring atoms cannot simultaneously exist in a Rydberg state due to their spatial “blockade” interaction. However, a laser pulse can induce a superposition where the system is simultaneously in a state with either atom excited, effectively entangling the pair to react collectively to signals.
Initially, the Rydberg atom sensor array consists of 25 qubits—each qubit representing a pair of entangled atoms—but plans are underway to scale this architecture to several hundred qubits. This scaling is vital for demonstrating the predicted quadratic improvements in measurement sensitivity and high-resolution sensing capabilities. The Rydberg array effort is led by Jeff Thompson, associate professor at Princeton’s Department of Electrical and Computing Engineering, and this collaboration exemplifies the project’s interdisciplinary and multi-institutional nature.
The second testbed adopts a completely different physical approach: a vibrational membrane sensor system. Comparable to how the human eardrum vibrates in response to sound waves, these membranes respond to incoming light waves, pushing the limits of optomechanical sensing. Under the leadership of Zhang at U-M, the team plans to upgrade a single membrane sensor into a four-sensor array, cooling these devices to temperatures near 0.1 Kelvin, just above absolute zero. In this ultracold regime, thermal noise is minimized, and quantum fluctuations become the dominant source of noise, challenging researchers to leverage quantum entanglement of light for measurement precision beyond classical noise limits.
Linking these membrane sensors via entangled light fields embodies the continuous-variable approach to quantum sensing, contrasting the discrete atomic qubits of the Rydberg system. Both discrete and continuous-variable quantum sensing techniques are crucial because they enable exploration of distinct physical regimes and offer complementary paths toward achieving entanglement-enhanced sensitivity. The experimentation with these testbeds will inform the design of quantum protocols for stable networking, including sophisticated error mitigation techniques imperative to preserve coherence and entanglement.
The ambitious project, formally titled “Discrete and Continuous-Variable Distributed Entangled Quantum Sensing: Foundation, Building Blocks, and Testbeds,” unites notable researchers from a consortium of universities: University of Michigan, Princeton University, University of Chicago, University of Maryland, University of Arizona, and University of Southern California. Such broad collaboration underscores the complexity and transformative potential of entangled quantum sensing networks and highlights strategic investment in quantum technologies.
Success in this endeavor promises to catalyze a quantum leap in sensor capabilities, enabling measurement sensitivity improvements that scale not just with the square root but quadratically with the number of sensors. This scaling advantage could redefine precision standards across multiple domains, from navigation and timing to electromagnetic field sensing. Furthermore, this research lays foundational work toward the realization of a quantum internet, wherein entanglement distribution empowers secure communication and distributed quantum computing.
As quantum technologies continue to transition from lab curiosities to real-world disruptive tools, the University of Michigan’s leading role in entangled quantum sensor networks places it at the forefront of this scientific and technological revolution. The outcomes from this project will provide crucial insights into harnessing quantum correlations at scale, potentially reshaping the landscape of metrology and quantum information science in the coming decades.
Subject of Research: Quantum entangled sensor networks and quantum sensing technologies
Article Title: Entangled Quantum Sensors: Ushering a New Era in Precision Measurement Networks
News Publication Date: [Not provided]
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Keywords
Quantum entanglement, quantum measurement, quantum optics, quantum mechanics, applied physics, quantum sensing, quantum networking, quantum error correction, Rydberg atoms, optomechanical sensors
Tags: distributed quantum sensor arraysentangled quantum sensorsfundamental limits of quantum sensorshigh-precision quantum sensingquantum data acquisition accelerationquantum entanglement in measurementquantum measurement fidelityquantum sensing technology innovationquantum sensor networksquantum signal-to-noise enhancementU.S. Office of Naval Research fundingUniversity of Michigan quantum research
