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 electrons feel the ionic potential in a crystal. A 7Li system is advantageous because its Feshbach resonances allow us to control the interactions between the atoms and the light mass of Li makes the dynamics faster. We use two hyperfine states modeling spin up and spin down to study magnetic ordering at 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.
We have recently investigated novel "phantom helix states" of 1D Heisenberg magnets and dynamics of spin transport in far out-of-equilibrium states (see Research). We have made progress on preparing the many-body ground state of the Heisenberg model (manuscript accepted in 2023). We are now upgrading our machine to incorporate single-site resolution with a high-NA microscope.