The impact of the injection protocol on an impurity’s stationary state

Oleksandr Gamayun 1, 2 Oleg Lychkovskiy 3, 4, 5 Evgeni Burovski 6, 7 Matthew Malcomson 8 Vadim V. Cheianov 1 Mikhail B. Zvonarev 9

Physical Review Letters, American Physical Society, 2018

We examine stationary state properties of an impurity particle injected into a one-dimensional quantum gas. We show that the value of the impurity's end velocity lies between zero and the speed of sound in the gas, and is determined by the injection protocol. This way, the impurity's constant motion is a dynamically emergent phenomenon whose description goes beyond accounting for the kinematic constraints of Landau approach to superfluidity. We provide exact analytic results in the thermodynamic limit, and perform finite-size numerical simulations to demonstrate that the predicted phenomena are within the reach of the existing ultracold gases experiments.

  • 1. Universiteit Leiden [Leiden]
  • 2. Bogolyubov Institute for Theoretical Physics
  • 3. Skoltech - Skolkovo Institute of Science and Technology [Moscow]
  • 4. Steklov Mathematical Institute of Russian Academy of Sciences
  • 5. Russian Quantum Center
  • 6. National Research University Higher School of Economics [Moscow]
  • 7. Science Center in Chernogolovka
  • 8. Lancaster University
  • 9. LPTMS - Laboratoire de Physique Théorique et Modèles Statistiques