Macroscopic Quantum Phenomena
Quantum physics is generally characterized as the science of the very small, but under certain circumstances quantum effects lead to dramatic changes in the properties of materials on macroscopic scales. ‘Macroscopic’ quantum phenomena involve collective behavior of enormous numbers of interacting quantum particles, and quantitative analysis of many of these systems (like high temperature superconductors) is extremely challenging. Many-body quantum systems are often difficult to handle theoretically, and in some important cases the true nature of the phase diagram is not yet accurately known. One possible path to gain deeper understanding of these incredibly rich physical systems is to engineer a “synthetic” many body quantum system that maps onto a particular system of interest, but has more conveniently tunable properties.
One important advantage to studying quantum states of matter using ultracold atoms is that we can control the interactions between the atoms by varying an externally applied magnetic field.The ability to make the interactions weak or strong, attractive or repulsive, allows us to extract far more information about a given system than when these parameters are not tunable, as is the case with most “real” condensed matter systems.