About

BEC 5 is the 7Li lab in the Ketterle group at MIT. We study ultracold bosons in optical lattices. The field of cold atoms in optical lattices is inspired by the possibility to simulate the behavior of electrons in crystals in a clean and controlled way. The atoms feel the dipole potential of the laser beams just as the electrons feel the ionic potential in a crystal. The advanages of a 7Li system include the possibility to control the interactions between the atoms via Feshbach resonances and the light mass of Li, which makes the dynamics faster. Using two hyperfine states to model spin up and spin down, our system could contribute to the study of magnetic ordering at very low temperatures (Quantum Magnetism). The proximity in the phase diagram of the quantum antiferromagnets to the superconducting state of high-temperature superconductors makes the study of magnetic ordering be of major interest. With the ability to switch interactions from attractive to repulsive, our system can favor antiferromagnetic ordering with bosons. Our system can simulate both spin 1/2 and spin 1, making it possible to explore different exotic phases and the quantum phase transitions between them. 

A major issue in realizing such ordered phases is the noise and heating involved with optical lattices. We are currently investigating the varios processes leading to heating and designing the next generation of stable optical lattices.