New quantum sensor could count individual photons and hunt dark matter
A Finnish research team has made a groundbreaking leap in ultra-sensitive measurement technology, detecting energy on the order of zeptojoules—far less than one trillionth of a joule. This breakthrough could revolutionize quantum computing, support dark matter searches, and enable precise photon counting. Quantum mechanics operates at atomic scales, and scientists are developing tools to measure such tiny phenomena. Greater precision opens doors to advanced quantum devices and deeper understanding of cosmic mysteries.
A zeptojoule is an extremely small unit of energy, equivalent to the work needed to move a red blood cell up a nanometer in Earth's gravity. The study’s success hinges on a unique setup involving a calorimeter and two types of conductive materials: superconductors (which allow electricity to flow freely) and normal conductors (which resist electrical flow). The combination creates a highly sensitive system, even when the temperature rises slightly. Professor Mikko Möttönen, who led the research at Aalto University, emphasized the fragile nature of superconductivity, noting its sensitivity to temperature changes. This setup allows for unprecedented precision in measuring signals from electromagnetic pulses, which could be used to detect dark-matter axions or other exotic particles.
This achievement marks the first time a calorimetric device has reached such sensitivity. The researchers believe the technology could become integral to quantum computers, as the calorimeter operates at millikelvin temperatures required by qubits. In the future, this setup might serve as a component for reading out quantum states, enabling more efficient processing of quantum information.
The research was conducted using facilities at OtaNano, Finland’s national research infrastructure for nano-, micro-, and quantum technologies. Funding came from initiatives like Future Makers, supported by the Jane and Aatos Erkko Foundation and the Technology Industries of Finland Centennial Foundation. This work highlights the potential of interdisciplinary collaboration in pushing the boundaries of quantum science.
