Anomalous hydrodynamics and normal fluids in rapidly rotating Bose-Einstein condensates.

Understanding fluid behavior in quantum systems remains an open challenge. Conventional hydrodynamics often fails at ultralow temperatures. Prior research has shown that superfluids exhibit unique properties. However, the role of rotation in these systems is not fully resolved. Rapid rotation can alter the dynamics of Bose-Einstein condensates. The quantum Hall regime introduces new constraints on fluid motion. No prior work had resolved how vortices interact with surface waves. This gap motivated a deeper investigation into anomalous hydrodynamics.

This study aims to explore the hydrodynamic regime in rapidly rotating Bose-Einstein condensates. The focus is on the quantum Hall regime and its implications. The researchers propose to examine the absence of a normal fluid in these systems. They also investigate how superfluid behavior deviates from classical models. The study addresses the role of vortices and surface waves in energy dissipation. The goal is to clarify the connection between vortex motion and fluid dynamics. The researchers aim to test if surface waves can mimic normal fluid behavior. This work seeks to provide a clearer framework for anomalous hydrodynamics.

The researchers use a mean field approach to model the quantum Hall regime. They analyze the spatial variations of density and phase in the system. The study incorporates constraints between these variables to describe fluid motion. Vortex positions are not used as the primary description of dynamics. Instead, the researchers focus on the relationship between vortices and surface waves. They simulate the absorption of energy and angular momentum by surface waves. The time scale of these processes is evaluated under different initial conditions. The study also considers how these effects relate to experimental observations at JILA.

The study reveals a regime of anomalous hydrodynamics in rapidly rotating Bose-Einstein condensates. The absence of a normal fluid is confirmed in this regime. Superfluid hydrodynamics deviates from the Bernoulli and continuity equations. The researchers observe constraints linking density and phase variations. Vortex positions are not sufficient to describe the system's dynamics. A simple relationship between vortices and surface waves is demonstrated. Surface waves can absorb energy and angular momentum from vortex motion. The time scale of this process depends on the initial configuration of the system.

The authors propose that anomalous hydrodynamics occurs in the quantum Hall regime. They suggest that superfluid behavior does not follow classical hydrodynamic models. The absence of a normal fluid is a key finding in this study. The researchers emphasize the role of surface waves in energy dissipation. Vortex motion is shown to interact with surface waves in a non-trivial way. The time scale of these interactions is sensitive to the system's initial state. The study supports the possibility of long-lived vortex patches in rotating condensates. These findings may relate to experimental observations at JILA.