Researchers around the world are racing to develop new quantum-based systems for sensing, communication, computing and control that have the promise of outperforming traditional systems. Creating stable, measurable, distinguishable quantum states—which would be the heart of any such system—is a daunting task.

Quantum states possess unique properties that can be exploited to develop novel information-processing systems. Two key properties, stability and distinguishability, are hard to achieve, however. Extracting information from a quantum system depends on the distinguishability of quantum states, an intrinsic property associated with a property known as orthogonality. Nevertheless, no two Gaussian states (a widely studied class of quantum states) are orthogonal, and this yields an unavoidable error when attempting to distinguish them.

In addition, present quantum devices tend to remain stable only for a fraction of a second and require complex protocols to distinguish states. Now, researchers at MIT and the University of Ferrara have found a new approach for creating easily distinguishable states that could help enable the development of these new quantum-based devices.