Coherent Stern–Gerlach momentum splitting on an atom chip

• Published in: Nature communications Vol. 4; no. 1; p. 2424
• Main Authors: Machluf, Shimon, Japha, Yonathan, Folman, Ron
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 09.09.2013; Nature Publishing Group
• Subjects: 639/766/119; 639/766/36; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms3424

In the Stern–Gerlach effect, a magnetic field gradient splits particles into spatially separated paths according to their spin projection. The idea of exploiting this effect for creating coherent momentum superpositions for matter-wave interferometry appeared shortly after its discovery, almost a century ago, but was judged to be far beyond practical reach. Here we demonstrate a viable version of this idea. Our scheme uses pulsed magnetic field gradients, generated by currents in an atom chip wire, and radio-frequency Rabi transitions between Zeeman sublevels. We transform an atomic Bose–Einstein condensate into a superposition of spatially separated propagating wavepackets and observe spatial interference fringes with a measurable phase repeatability. The method is versatile in its range of momentum transfer and the different available splitting geometries. These features make our method a good candidate for supporting a variety of future applications and fundamental studies. In a Stern–Gerlach interferometer, atoms are split by a magnetic field gradient into two paths according to their spin. Here, the authors apply this principle to a Bose–Einstein condensate to demonstrate on-chip coherent splitting of atomic wavepackets and cold atom interferometry.