Scientists in the quantum light & matter group at Durham University have set a new world-record for quantum coherence in ultracold molecules, in a collaboration with theorists at Temple University and Rice University.

Experiments at Durham are able to cool gases of atoms and molecules down to a millionth of a degree above absolute zero. At these incredibly low temperatures, the effects of quantum mechanics can be studied with unparalleled precision.

Prof. Simon Cornish and Dr. Philip Gregory lead an experiment to study RbCs molecules at ultracold temperatures. One attractive feature of these molecules is that quantum information can be encoded into their rotation. However, typically this information is lost by decoherence over a few milliseconds.

In their latest experiments, published in Nature Physics, they have developed a technique using a magic trap for the molecules which significantly suppresses this decoherence. In this trap, they were able to keep the molecules “spinning” quantum mechanically for over 1 second. A 30-fold increase over the previous state of the art.

The researchers said: “Until now, quantum decoherence has been a significant issue for experiments on ultracold molecules. One second coherence times are a significant step forward for the field. Crucially they allow us to detect long-range dipolar interactions between molecules, opening up applications in quantum computing, quantum simulation and quantum sensing.”