- Sandia National Laboratories has developed a low-power quantum sensor that requires only 5 milliwatts.
- Quantum navigation systems are less susceptible to interference and offer high accuracy, addressing the vulnerability of satellite signals.
- The research team is working on integrating quantum sensors into photonic circuits to enhance stability for field applications.
- The findings have been published in the journal AVS Quantum Science.
Researchers at the US Sandia National Laboratories have developed a quantum sensor that requires only 5 milliwatts of power—about 1/2,000th of a standard LED bulb—and uses an optical fiber that is just 420 nanometers thick, or 200 times thinner than a human hair. The development of this sensor and its related technologies paves the way for the practical application of quantum sensing technology. The world today relies heavily on satellite signals for navigation, from app-based taxis, commercial aircraft, and cargo ships at sea, to military drones engaged in combat, all of which depend on satellite signals to determine their position and navigate to their destinations.
With such high reliance, systems can be easily crippled by jamming or spoofing satellite signals, which can be achieved through electromagnetic noise that overwhelms these signals.
The Advantages of Quantum Navigation Systems
To address this issue, scientists have been researching quantum-based navigation systems that are not only less susceptible to interference but also offer extremely high accuracy. There are several different methods by which these systems operate, one of which is free-space atom interferometry. In this method, ultracold atoms are released into a vacuum chamber and their motion is measured using lasers. However, vibrations or other disturbances can make these measurements unreliable, prompting scientists to seek more stable methods. The tightly confined light-guided atom interferometry method uses non-fiber devices to guide atoms, similar to marbles flowing through a narrow pipe, ensuring they are always observed by lasers.
Jongmin Lee, a quantum sensing scientist at Sandia National Laboratories, has been working on creating an extremely compact device that consumes very little power and can be used in field applications. Lee's ambition is to place this device on a photonic integrated circuit so that measurements can continue even if the device is bumped. In real-world scenarios, this could support navigation for vehicles traversing rough terrain or aircraft experiencing turbulence. As Lee explained in a press release, "The reason this idea has not been realized by society for decades is due to the challenge of dissipating heat in a vacuum and the difficulty of effectively loading atoms."
Innovations in Solving Thermal Load Issues
Lasers need to create a halo effect to guide and count moving atoms. However, these are also the main sources of heat in the system, especially when dealing with components like nanofibers that are much thinner than a human hair. In this situation, scientists always have to make trade-offs. Either they use a fragile design that can load atoms well but is prone to breaking under high heat, or they use a robust design that can handle heat well but cannot effectively load atoms. The researchers at Sandia National Laboratories, led by Lee, solved this problem by using small silicon needles to secure the waveguide on both sides and act as heat sinks.
Lee added in the press release, "Based on our nanofiber research results, we have demonstrated that cesium atoms can be trapped with only five milliwatts of optical power, and the atomic coherence can be measured using a sub-microwatt fiber-coupled beam while minimizing the thermal load in the vacuum."
After solving some of the issues in the setup, the team hopes to integrate the guide and other components onto a single chip and build an array of inertial quantum sensors. These research findings have been published in the journal AVS Quantum Science.
The Impact of Quantum Sensors on Navigation Technology
As navigation technology becomes increasingly reliant on satellite signals, the development of quantum sensors is particularly crucial. These sensors not only resist external interference but also maintain high accuracy in a variety of extreme environments, which is a significant advancement for military, commercial, and civilian navigation systems. The research at Sandia National Laboratories not only demonstrates the potential of quantum technology in field applications but also solves the long-standing problem of thermal load, paving the way for future quantum navigation systems.