R-mode oscillations and rocket effect in rotating superfluid neutron stars. I. Formalism

Dissipative processes in superfluid neutron stars

We present some results about a novel damping mechanism of r-mode oscillations in neutron stars due to processes that change the number of protons, neutrons and electrons. Deviations from equilibrium of the number densities of the various species lead to the appearance in the Euler equations of the system of a dissipative mechanism, the so-called rocket effect. The evolution of the r-mode oscillations of a rotating neutron star are influenced by the rocket effect and we present estimates of the corresponding damping timescales. In the description of the system we employ a two-fluid model, with…

Dissipative processes in superfluid quark matter

We present some results about dissipative processes in fermionic superfluids that are relevant for compact stars. At sufficiently low temperatures the transport properties of a superfluid are dominated by phonons. We report the values of the bulk viscosity, shear viscosity and thermal conductivity of phonons in quark matter at extremely high density and low temperature. Then, we present a new dissipative mechanism that can operate in compact stars and that is named "rocket term". The effect of this dissipative mechanism on superfluid r-mode oscillations is sketched.

Multiple-quantized vortices in rotating LOFF state of ultracold Fermi superfluid gas

A rotating ultracold S-wave superfluid Fermi gas is considered, when the population imbalance (or equivalently the mismatch in chemical potentials) corresponds to the Larkin-Ovchinnikov-Fulde-Ferrell (LOFF) state in the vicinity of the Lifshitz critical point. It is shown that under these conditions the critical angular velocity in two-dimensional systems is an oscillating function of temperature and population imbalance giving rise to reentrant superfluid phases. This leads to vortex lattices with multiple-quantized circulation quanta. The reason for this behavior is the population by Cooper …

超流体中的旋转量子摩擦：超流体真空中旋转物体的辐射

Rotational quantum friction in superfluids: Radiation from object rotating in superfluid vacuum

讨论了T=0时物体在超流液体中旋转时所受的摩擦力。这种效应类似于在量子真空中旋转的物体或黑洞对电磁辐射和自发发射的放大，首先由泽尔多维奇和斯塔罗宾斯基讨论。摩擦是由液体的一部分与旋转体刚性连接并因此代表共动检测器的液体与体外的“闵可夫斯基”真空的相互作用引起的。发射过程是准粒子从探测器到各能区的量子隧穿，在转动系中，各能区的准粒子能量为负。这种量子转动摩擦所造成的准粒子的排放估计声子和转动子在超流4He和Bogoliubov费米子在超流3He。

Spin vortex lattice in the Landau vortex-free state of rotating superfluids

We show that the Landau vortex-free state in rotating container may give rise to the lattice of spin vortices. We consider this effect on example of spin vortices in magnon Bose-Einstein condensate (the phase coherent spin precession) in the B-phase of superfluid $^3$He, and on example of spin vortices in the polar phase of $^3$He.

Formation of topological vortices during superfluid transition in a rotating vessel

Formation of topological defects during symmetry breaking phase transitions via the {\it Kibble mechanism} is extensively used in systems ranging from condensed matter physics to the early stages of the universe. Kibble mechanism uses topological arguments and predicts equal probabilities for the formation of defects and anti-defects. Certain situations, however, require a net bias in the production of defects (or antidefects) during the transition, for example, superfluid transition in a rotating vessel, or flux tubes formation in a superconducting transition in the presence of external magne…