arXiv subjects

P. Krüger

Publications and source records attributed to P. Krüger.

22 records · Page 2Linked to original sources

arXiv2004

Atom Chips: Fabrication and Thermal Properties

Neutral atoms can be trapped and manipulated with surface mounted microscopic current carrying and charged structures. We present a lithographic fabrication process for such atom chips based on evaporated metal films. The size limit of this process is below 1$μ$m. At room temperature, thin wires can carry more than 10$^7$A/cm$^2$ current density and voltages of more than 500V. Extensive test measurements for different substrates and metal thicknesses (up to 5 $μ$m) are compared to models for the heating characteristics of the microscopic wires. Among the materials tested, we find that Si is the best suited substrate for atom chips.

cond-mat.mtrl-sci↗

arXiv2003

An atom fiber for guiding cold neutral atoms

We present an omnidirectional matter wave guide on an atom chip. The rotational symmetry of the guide is maintained by a combination of two current carrying wires and a bias field pointing perpendicular to the chip surface. We demonstrate guiding of thermal atoms around more than two complete turns along a spiral shaped 25mm long curved path (curve radii down to 200$μ$m) at various atom--surface distances (35-450$μ$m). An extension of the scheme for the guiding of Bose-Einstein condensates is outlined.

quant-ph↗

arXiv2003

Optimized U-MOT for experiments with ultracold atoms near surfaces

We present an integrated wire-based magnetooptical trap for the simplified trapping and cooling of large numbers of neutral atoms near material surfaces. With a modified U-shaped current-carrying Cu structure we collect $>3\times 10^8$ $^{87}$Rb atoms in a mirror MOT without using quadrupole coils. These atoms are subsequently loaded to a Z-wire trap where they are evaporatively cooled to a Bose-Einstein condensate close to the surface.

cond-mat.soft↗

arXiv2003

Trapping and manipulating neutral atoms with electrostatic fields

We report on experiments with cold thermal $^7$Li atoms confined in combined magnetic and electric potentials. A novel type of three-dimensional trap was formed by modulating a magnetic guide using electrostatic fields. We observed atoms trapped in a string of up to six individual such traps, a controlled transport of an atomic cloud over a distance of 400$μ$m, and a dynamic splitting of a single trap into a double well potential. Applications for quantum information processing are discussed.

quant-ph↗