Guiding Neutral Atoms Around Curves with Lithographically Patterned Current-Carrying Wires

Abstract

Laser-cooled neutral atoms from a low-velocity atomic source are guided via a magnetic field generated between two parallel wires on a glass substrate. The atoms bend around three curves, each with a 15-cm radius of curvature, while traveling along a 10-cm-long track. A maximum flux of 2 · 10 6 atoms/sec is achieved with a current density of 3 · 10 4 A/cm 2 in the 100 × 100-µm-cross-section wires. The kinetic energy of the guided atoms in one transverse dimension is measured to be 42 µK. PACS numbers: 03.75.B, 32.80.P Just as optical waveguides play a central role in many aspects of modern optics, from communications to integrated optics, atom waveguides are likely to be an enabling technology for future atom-optics-based science. In particular, well-characterized atom waveguides may make possible inertial and rotation measurements of exquisite sensitivity via large-enclosed-area atom interferometers [1]. One of the first guides for atoms was based on optical forces, where hollow glass fibers guide light, and the light in turn guides atoms [2,3].Atom guiding using magnetic forces from current-carrying wires has been demonstrated more recently [4,5]. From the point-of-view of using atom-guides to pursue precision metrology goals [6] much benefit can be derived from patterning the waveguides on a rigid substrate. First, beamsplitters can be precisely and reproducibly fabricated.Second, the enclosed area of an interferometer can be precisely controlled. Third, the use of well-established lithographic techniques means that progress on individual optical elements (a beamsplitter, or a monochromator, for instance) can be rapidly extended to multi-component experiments. Mirrors based on micro-patterned wires have already been introduced [7]. We report magnetic guiding by a pair of parallel wires produced on a glass substrate by photolithography and subsequent electro-plating. Intricate two-dimensional guiding structures are easily produced by this manufacturing technique; in the present case, it allows us to demonstrate guiding around curves in a 10 cm long

Atom interferometry using wave packets with constant spatial displacements

“…By accounting for gravity, atomic fountains can increase the interrogation time during which the interferometry phase shifts accumulate [2]; alternatively one can use magnetic dipole forces to balance the force of gravity [3]. Magnetic waveguides [4,5] can trap atoms for times longer than a second, suggesting the possibility of measuring energy differences between interfering wave packets with an uncertainty <h/(1 s) ∼ 10 −34 J; however, this remarkable precision cannot be obtained if the decoherence time of the atoms is much shorter than the trap lifetime. Early atom interferometry experiments using atoms confined in magnetic waveguides showed that the external state coherence of the atoms decayed quite quickly, limiting interferometric measurements to times <10 ms [6,7].…”

Effective interactions, Fermi–Bose duality, and ground states of ultracold atomic vapors in tight de Broglie waveguides

“…It is now known that this "Fermi-Bose duality" is a very general property of identical particles in 1D, not restricted to the hard-sphere model, and relating strongly interacting bosons to weakly-interacting fermions and vice versa. In recent years this esoteric subject has become highly relevant through experiments on ultracold atomic vapors in atom waveguides [3][4][5][6][7][8][9][10][11]. An understanding of their properties is important for atom interferometry [12,13] and integrated atom optics [11,14,15], which are potentially important for development of ultrasensitive detectors of accelerations and gravitational anomalies.…”

Trapped-atom interferometer in a magnetic microtrap

“…Since the first realization of magnetic traps [1,2] and guides [3,4] with current-carrying conductors on a chip, a large variety of magnetic potentials have become experimentally accessible, which would be impractical or even impossible to realize with macroscopic coils. The splitting of two-dimensionally trapped atom clouds has been demonstrated [5,6], and recently, we were able to split and unite a three-dimensionally trapped cloud of rubidium atoms in a chip trap [7].…”