Bichromatic slowing of metastable helium

Thermodynamics of metastable superfluid helium

Using Landau’s theory of elementary excitations together with a simple model for the interactions between excitations, we calculate the thermodynamic properties of superfluid helium-4 at pressures below the saturated vapor pressure and above the normal freezing temperature. r 2003 Elsevier Science B.V. All rights reserved. PACS: 67.40.Kh; 67.40.Bz; 67.40.Db

Atom lithography with metastable helium

A bright metastable helium He beam is collimated sequentially with the bichromatic force and three optical molasses velocity compression stages. Each He atom in the beam has 20 eV of internal energy that can destroy a molecular resist assembled on a gold coated silicon wafer. Patterns in the resist are imprinted onto the gold layer with a standard selective etch. Patterning of the wafer with th...

Ultracold collisions of metastable helium atoms

We report scattering lengths for the Σg , Σu and Σg adiabatic molecular potentials relevant to collisions of two metastable 2 3S helium atoms as a function of the uncertainty in these potentials. These scattering lengths are used to calculate experimentally observable scattering lengths, elastic cross sections and inelastic rates for any combination of states of the colliding atoms, at temperat...

Long-range interactions of metastable helium atoms

Polarizabilities, dispersion coefficients, and long-range atom-surface interaction potentials are calculated for the n = 2 triplet and singlet states of helium using highly accurate, variationally determined, wave functions. PACS numbers: 34.20.Cf, 32.10.Dk, 34.50.Dy Typeset using REVTEX 1 The advent of doubled basis sets has made it possible to calculate precisely many properties of two-electr...

Ultracold metastable calcium atoms in a bichromatic magneto-optical trap