Physical Review A · 2004 · 301 citations · 22 references
Natural SciencesPhysicsCondensed Matter PhysicsFluid DynamicsThermodynamicsStates Of MatterStatistical MechanicsBose-einstein CondensationCorrelation FunctionsDrag ForceDrag Force ModelingSupersonic FlowVelocity
The drag force appears for supersonic motion of the impurity. We study the motion of a point‑like impurity in a Bose–Einstein condensate at zero temperature, calculating its induced mass and drag force in 3D, 2D, and 1D via perturbative Gross–Pitaevskii solutions. By solving the Gross–Pitaevskii equation perturbatively and, in 1D, employing the exact Lieb–Liniger theory with the dynamic form factor evaluated by the Haldane method, we compute the induced mass and drag force. The induced mass agrees with Bogoliubov theory, the drag force appears for supersonic motion overall but already at arbitrarily small velocities in 1D, and the dynamic form factor could be measured in current experiments.
We study motion of a point-like impurity in a Bose-Einstein condensate at T=0. By solving the Gross-Pitaevskii equation in a perturbative manner we calculate the induced mass of the impurity and the drag force on the impurity in 3D, 2D and 1D cases. The relationship between the induced mass and the normal mass of fluid is found and coincides with the result of the Bogoliubov theory. The drag force appears for supersonic motion of the impurity. In 1D the drag force is investigated also on the basis of the exact Lieb-Liniger theory, using the dynamic form factor, which has been evaluated by the Haldane method of the calculation of correlation functions. In this theory the force appears for an arbitrarily small velocity of the impurity. The possibility of measuring the form factor in existing experiments is noted.
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