Related papers: Rotation in liquid $^4$He: Lessons from a toy mode…
The damping of collective rotational motion is investigated by means of particles-rotor model in which the angular momentum coupling is treated exactly and the valence nucleons are in a multi-$j$ shell mean-field. It is found that the onset…
We present the results of large-scale numerical simulations of the mobility of a two-dimensional electron liquid on the helium surface in the presence of a one-dimensional periodic potential. Even where the potential is much weaker than the…
We present three-dimensional Monte-Carlo simulations of the capture of 1000 K $^7$Li or 500 K $^{87}$Rb atoms by a continuous supersonic $^4$He jet and show that intense alkali-metal beams form with narrow transverse and longitudinal…
A two-dimensional rapidly rotating Bose-Einstein condensate in an anharmonic trap with quadratic and quartic radial confinement is studied analytically with the Thomas-Fermi approximation and numerically with the full time-independent…
We investigate the dynamics of a Bose-Einstein condensate of magnetic atoms in which the dipoles are rotated by an external magnetic field. The time-averaged dipole-dipole interaction between the atoms is effectively tuned by this rotation,…
Molecular helium represents a benchmark system for testing $\textit{ab initio}$ calculations on few-electron molecules. We report on the determination of the adiabatic ionization energy of the $a\,^3\Sigma_u^+$ state of He$_2$,…
The effects of particle roughness and short-ranged non-central forces on colloidal gels are studied using computer simulations in which particles experience a sinusoidal variation in energy as they rotate. The number of minima $n$ and…
We report extensive theoretical calculations on the rotation-inversion excitation of interstellar ammonia (NH3) due to collisions with atomic and molecular hydrogen (both para- and ortho-H2). Close-coupling calculations are performed for…
Motivated by recent experiments, we model the dynamics of a condensed Bose gas in a rotating anisotropic trap, where the equations of motion are analogous to those of charged particles in a magnetic field. As the rotation rate is ramped…
We examine the energetics of bulk and layer-roton excitations of 4He in various porous medial such as aerogel, Geltech, or Vycor, in order to find out what conclusions can be drawn from experiments on the energetics about the physisorption…
Utilizing the recently established connection between Palatini-like gravity and linear Generalized Uncertainty Principle (GUP) models, we have formulated an approach that facilitates the examination of Bose gases. Our primary focus is on…
We consider a BEC of rigid rotor molecules confined to quasi-2d through harmonic trapping. The molecules are subjected to an external electric field which polarizes the gas, and the molecules interact via dipole-dipole interactions. We…
We study a polar molecule immersed into a superfluid environment, such as a helium nanodroplet or a Bose-Einstein condensate, in the presence of an intense electrostatic field. We show that coupling of the molecular pendular motion, induced…
Integrating seminal ideas of London, Feynman, and Feenberg, this paper continues the development of an ab initio theory of the lambda transition in liquid 4He. The theory is based on variational determination of a trial density matrix…
We study the low temperature properties of a helium-4 fluid confined in nanopores, using large-scale Quantum Monte Carlo simulations with realistic He-He and He-pore interactions. In the narrow-pore limit, the system can be described by the…
Molecular rotors form twisted conformations upon photoexcitation, with their fluorescent relaxation time serving as a measure of viscosity. They have been used to assess membrane viscosities but yield higher values compared to other…
We study superfluid helium droplets multiply charged with ions. When stable, the charges are found to reside in equilibrium close to the droplet surface, thus representing a physical realization of Thomson's model. We find the minimum…
In this paper, we report experimental results on the shape and motion of a mercury droplet, placed in a horizontally rotating cylinder in the rpm range 8-93, so that the Reynolds number of the drop 2500<Re<26000 and its capillary number…
Following excitation by a strong ultra-short laser pulse, molecules develop coordinated rotational motion, exhibiting transient alignment along the direction of the laser electric field, followed by periodic full and fractional revivals…
Bose-Einstein condensation of rotons in helium was considered long ago. It was shown that the relative velocity of the normal motion in this state must be equal to the Landau critical velocity. We argue that the condensation can be attained…