Kelvin-Helmholtz instability in two-component Bose gases on a lattice

Crossover between Kelvin-Helmholtz and counter-superflow instabilities in two-component Bose-Einstein condensates

Dynamical instabilities at the interface between two Bose--Einstein condensates that are moving relative to each other are investigated using mean-field and Bogoliubov analyses. Kelvin--Helmholtz instability is dominant when the interface thickness is much smaller than the wavelength of the unstable interface mode, whereas the counter-superflow instability becomes dominant in the opposite case. These instabilities emerge not only in an immiscible system but also in a miscible system where an interface is produced by external potential. Dynamics caused by these instabilities are numerically dem…

环形超流体在UFG-BCS渡越区中的开尔文-亥姆霍兹不稳定性

Kelvin-Helmholtz instability in annular superfluids across the UFG-BCS crossover

本文采用含时超流体密度泛函理论，研究环形费米超流体在UFG-BCS渡越区的开尔文-亥姆霍兹不稳定性，揭示了不同相互作用区的动力学差异，为相关研究提供微观基准并约束实验-理论差异的解释。

Kelvin-Helmholtz instability in an atomic superfluid

We demonstrate an experimentally feasible method for generating the classical Kelvin-Helmholtz instability in a single component atomic Bose-Einstein condensate. By progressively reducing a potential barrier between two counter-flowing channels we seed a line of quantised vortices, which precede to form progressively larger clusters, mimicking the classical roll-up behaviour of the Kelvin-Helmholtz instability. This cluster formation leads to an effective superfluid shear layer, formed through the collective motion of many quantised vortices. From this we demonstrate a straightforward method t…

Pattern formation of quantum Kelvin-Helmholtz instability in binary superfluids

We study theoretically nonlinear dynamics induced by shear-flow instability in segregated two-component Bose-Einstein condensates in terms of the Weber number, defined by extending the past theory on the Kelvin-Helmholtz instability in classical fluids. Numerical simulations of the Gross-Pitaevskii equations demonstrate that dynamics of pattern formation is well characterized by the Weber number $We$, clarifying the microscopic aspects unique to the quantum fluid system. For $We \lesssim 1$, the Kelvin-Helmholtz instability induces flutter-finger patterns of the interface and quantized vortice…

由旋转触发的三组分玻色-爱因斯坦凝聚体中的凯尔文-赫姆霍兹与反超流不稳定性

Rotation-triggered Kelvin-Helmholtz and counter-superflow instabilities in a three-component Bose-Einstein condensate

研究三组分玻色-爱因斯坦凝聚体中旋转触发的凯尔文-赫姆霍兹与反超流不稳定性，通过调控界面相对运动探讨多组分量子流体动力学。

Quantum Kelvin-Helmholtz instability in phase-separated two-component Bose-Einstein condensates

We theoretically study the Kelvin-Helmholtz instability in phase-separated two-component Bose-Einstein condensates using the Gross-Pitaevskii and Bogoliubov-de Gennes models. A flat interface between the two condensates is shown to deform into sawtooth or Stokes-like waves, leading to the formation of singly quantized vortices on the peaks and troughs of the waves. This scenario of interface instability in quantum fluids is quite different from that in classical fluids.