Pinning quantum phase transition for a Luttinger liquid of strongly interacting bosons

摘要: Fluctuations arising from Heisenberg's uncertainty principle enable quantum systems to exhibit phase transitions even at zero temperature. For example, a superfluid-to-insulator transition has been observed for weakly interacting bosonic atomic gases. Here the authors report novel type of in strongly interacting, one-dimensional gas caesium atoms. The results open up experimental study ultracold gases new regime. Quantum many-body can have transitions1 temperature; fluctuations Heisenberg’s principle, as opposed thermal effects, drive system one another. Typically, during relative strength two competing terms system’s Hamiltonian changes across finite critical value. A well-known example is Mott–Hubbard superfluid an insulating phase2,3, which However, confined lower-dimensional geometry, type4,5 may be induced and driven by arbitrarily weak perturbation Hamiltonian. we observe such effect—the sine–Gordon Luttinger liquid Mott insulator6,7—in atoms with tunable interactions. sufficiently strong interactions, adding optical lattice commensurate granularity, leads immediate pinning We map out diagram find that our measurements regime agree well field description based on exactly solvable model8. trace boundary all way regime, where good agreement predictions Bose–Hubbard model. Our transitions, criticality transport phenomena beyond Hubbard-type models context