Superfluid stability near Landau critical velocity
نویسندگان
چکیده
منابع مشابه
Critical Landau velocity in helium nanodroplets.
The best-known property of superfluid helium is the vanishing viscosity that objects experience while moving through the liquid with speeds below the so-called critical Landau velocity. This critical velocity is generally considered a macroscopic property as it is related to the collective excitations of the helium atoms in the liquid. In the present work we determine to what extent this concep...
متن کاملCritical Currents in Superfluid Helium Near T ,
The temperature dependence of the critical heat current Q, in He I1 has been measured in the temperature region 3. ("K) < T,-T< 1.2-("K). The result Qca(T,-~)1.07*0.01 is consistent with a divergent mutual friction near T, proposed recently by AHLERS. I. Introduction The resistanceless flow of superfluid helium is limited by critical relative velocities (v,-us), between its normal and superflui...
متن کاملCritical velocity for superfluid flow across the BEC-BCS crossover.
Critical velocities have been observed in an ultracold superfluid Fermi gas throughout the BEC-BCS crossover. A pronounced peak of the critical velocity at unitarity demonstrates that superfluidity is most robust for resonant atomic interactions. Critical velocities were determined from the abrupt onset of dissipation when the velocity of a moving one-dimensional optical lattice was varied. The...
متن کاملCritical superfluid velocity in a trapped dipolar gas.
We investigate the superfluid properties of a dipolar Bose-Einstein condensate (BEC) in a fully three-dimensional trap. Specifically, we estimate a superfluid critical velocity for this system by applying the Landau criterion to its discrete quasiparticle spectrum. We test this critical velocity by direct numerical simulation of condensate depletion as a blue-detuned laser moves through the con...
متن کاملCritical Ultrasonics near the Superfluid Transition : Finite Size Effects
The suppression of order parameter fluctuations at the boundaries causes the ultrasonic attenuation near the superfluid transition to be lowered below the bulk value . We calculate explicitly the first deviation from the bulk value for temperatures above the lambda point . This deviation is significantly larger than for static quantities like the thermodynamic specific heat or other transport p...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Physics: Conference Series
سال: 2009
ISSN: 1742-6596
DOI: 10.1088/1742-6596/150/3/032057