Berlin 2018 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 85: Focus Session: Emergent Phenomena in Driven Quantum Many-Body Systems (joint session DY/TT)

TT 85.5: Vortrag

Donnerstag, 15. März 2018, 11:00–11:15, EB 107

Creating a superfluid by kinetically driving a Mott insulator — Gregor Pieplow, Fernando Sols, and •Charles Creffield — Universidad Complutense, Madrid, Spain

We study the effect of time-periodically varying the hopping amplitude (which we term ``kinetic driving'') in a one-dimensional Bose-Hubbard model, such that its time-averaged value is zero. By using Floquet analysis, we derive a static effective Hamiltonian in which nearest-neighbor single-particle hopping processes are suppressed, but all even higher-order processes are allowed. Unusual many-body features arise from the combined effect of non-local interactions and correlated tunneling. At a critical value of the driving, the system passes from a Mott insulator to a superfluid formed by two quasi-condensates with opposite nonzero momenta. A many-body cat state combining the two macroscopically occupied momentum eigenstates emerges even with hard-wall boundary conditions. This work shows how driving of the hopping energy provides a novel form of Floquet engineering, which enables atypical Hamiltonians and exotic states of matter to be produced and controlled.