Quantum flutter: signatures and robustness.
We investigate the motion of an impurity particle injected with finite velocity into an interacting one-dimensional quantum gas. Using large-scale numerical simulations based on matrix product states, we observe and quantitatively analyze long-lived oscillations of the impurity momentum around a nonzero saturation value, called quantum flutter. We show that the quantum flutter frequency is equal to the energy difference between two branches of collective excitations of the model. We propose an explanation of the finite saturation momentum of the impurity based on the properties of the edge of the excitation spectrum. Our results indicate that quantum flutter exists away from integrability and provide parameter regions in which it could be observed in experiments with ultracold atoms using currently available technology.
Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA and ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA and Institute of Theoretical and Computational Physics, Graz University of Technology, 8010 Graz, Austria.
Michael
M
Knap
Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA and ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA.
Charles J M
CJ
Mathy
Institute of Theoretical and Computational Physics, Graz University of Technology, 8010 Graz, Austria.
Martin
M
Ganahl
Univ Paris-Sud, Laboratoire LPTMS, UMR8626, Orsay, F-91405, France and CNRS, Orsay, F-91405, France.
Mikhail B
MB
Zvonarev
Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Eugene
E
Demler