Scientists at JILA, a joint institute of NIST and CU-Boulder, have created the first high-density gas of ultracold polar molecules. This breakthrough, published in Science Express, represents a significant advancement in the field of quantum physics and has potential applications in quantum computing, precision measurement, and designer chemistry.
The researchers combined potassium and rubidium atoms, which are different classes of atoms (a slightly negative fermion and a slightly positive boson), to create the polar molecules. These molecules exhibit a permanent and significant differential in electric charge, allowing them to exert strong forces on each other. The resulting molecules are relatively stable, with a measurable separation of electric charge and a long lifespan of about 30 milliseconds.
The process for making the molecules begins with a gas mixture of very cold potassium and rubidium atoms confined by a laser beam. By sweeping a precisely tuned magnetic field across the atoms, scientists create large, weakly bound molecules containing one atom of each type. The scientists then use two lasers operating at different frequencies to convert the binding energy into light instead of heat, efficiently converting more than 80 percent of the molecules to the lowest and most stable energy level.
Practical benefits of this research could include new chemical reactions and processes for making designer materials, new methods for quantum computing using charged molecules as quantum bits, new tools for precision measurement, and improved understanding of condensed matter phenomena. JILA researchers are now working to improve the efficiency of producing tightly bound polar molecules and extend molecule lifetimes.
Keywords: molecules, quantum, cold, atoms, interactions
