Quantum Optics asks fundamental questions such as: 'What is Light?' 'What is Matter?' and most importantly 'What is Quantum?' The answers can be elegant, surprising, and even useful.

To study the quantum physics of light and matter, we use the best tools available to modern science. We use ultra-cold atoms and ultra-high coherence photons to study exotic effects such as entanglement and squeezing. Where atoms and photons meet, this is where we have the most fun.

But Quantum Optics is not just fun: The fundamental physics we study has the potential to revolutionize communications, information processing, and especially sensing and measurement. Above: in experiments like this one entangled photons and atoms can detect truly tiny magnetic fields, at the quantum limits of sensitivity. Such precise measurements may some day be useful for applications ranging from space science to diagnosis of heart disorders.