In the project entitled "Quantum Engineering with Dissipation," we create and study strongly interacting quantum degenerate atomic gases, with a focus on systems in which correlations are induced by strong inelastic, or dissipative, interactions. Dissipation is emerging as a new tool for quantum engineering for creating novel states of fundamental interest. We use dissipation to create spatial correlations in strontium condensates in three-dimensional optical lattices and study the dissipative analog of the superfluid-to-Mott-insulator transition. An optical Feshbach resonance is used to create two-body inelastic interactions, and the effects of three-body inelastic interactions can be explored with Sr-86, which naturally has a large three-body decay rate. There are many interesting properties to study in these systems, such as the criteria for creation of particle correlations, excitation spectra, and adiabaticity timescales for changing lattice and interaction parameters. In addition, in a bulk system we will look at the response of a Bose condensate to a rapid quench of the interaction strength from the weakly interacting to the strongly interacting regime, which can be produced with an optical Feshbach resonance. Of interest to experiments in a bulk system and lattice is the timescale for development of spatial correlations in the many-body state.
When large numbers of particles come together and interact, new phenomena can emerge that are unexpected from the basic form of the interaction between pairs of particles. Superconductivity is a famous example of this. Understanding strongly interacting, many-body systems is a grand challenge for many areas of physics because of the promise of new material properties of technological significance and also because the systems can be very complicated and they stretch our understanding of the natural world.
In the last decade, there have been great advances in the creation and study of ultracold clouds of gaseous atoms, which are cooled by lasers to temperatures around a millionth of a degree above absolute zero. Ultracold atoms made in this way have the amazing property that their interactions can be arbitrarily controlled, which opens the possibility of using them to make designer materials or test models of interacting, many-body systems. With the support of this National Science Foundation grant, Prof. Killian's research group at Rice University in Houston, Texas will develop new techniques for manipulating atom-atom interactions using lasers and search for new emergent phenomena.
This work will involve at least two graduate students and one undergraduate student, and it will train them for high-technology careers in optics or materials. This work will also involve undergraduate researchers in summer research and work during the academic terms leading to honors research theses. Basic atomic physics experiments such as these lay the scientific and human resources foundation today for the technological marvels of tomorrow.
