A Universal Anti/Matter-Wave Interferometer to Test UFF

Nearly 90 years ago Louis de Broglie predicted the existence of matter-waves. With this claim every massive object got a new property, the phase, a property which does not exist in a classical world. In the last decades experimental advances have allowed us to extend proof of principle experiments and use this wave property of matter, in a very sophisticated way to measure classical forces in a quantum enhanced way. An important milestone was set by using laser light to coherently manipulate matter-waves. With this innovation very sensitive atom interferometers [1] with high momentum beam splitters [2] and interference times of up to 2.3 seconds were built [3]. Austria is one of the leading countries in matter-wave optic with complexand massiveexperiments [4]. While new opticalmatter-wave interferometers [5] for massive and complex particles work universally, which means that the interferometer arrangement operates independent for many particle classes, modern atom interferometers are often specifically adapted to the optical transition of a certain atom. Even the change to another isotope of the same element requires a technological effort [6]. A possible way to overcome these restrictions and to build up a universal optical interferometer for all atomic elements is given by far off-resonant high power laser pluses which couple to the static electric polarizability of the atoms [7]. The main aim of my stay at the UC Berkeley is the experimental realisation of a universal anti/matter-wave interferometer in the Bragg- regime especially for light neutral particles like hydrogen/antihydrogen, helium and lithium, but also for charged ones like electrons/positrons. [1]S.-Y. Lan, P.-C. Kuan, B. Estey, P. Haslinger, and H. Müller, Phys. Rev. Lett. 108, 090402 (2012). [2]S. Chiow, T. Kovachy, H.-C. Chien, and M. Kasevich, Phys. Rev. Lett. 107, 130403 (2011). [3]S. M. Dickerson, J. M. Hogan, A. Sugarbaker, D. M. S. Johnson, and M. A. Kasevich, Phys. Rev. Lett. 111, 083001 (2013). [4]K. Hornberger, S. Gerlich, P. Haslinger, S. Nimmrichter, and M. Arndt, Rev. Mod. Phys. 84, 157 (2012). [5]P. Haslinger, N. Dörre, P. Geyer, J. Rodewald, S. Nimmrichter, and M. Arndt, Nat. Phys. 9, 144 (2013). [6]A. Bonnin, N. Zahzam, Y. Bidel, and A. Bresson, Phys. Rev. A 88, 043615 (2013). [7]P. Hamilton, A. Zhmoginov, F. Robicheaux, J. Fajans, J. S. Wurtele, and H. Müller, Phys. Rev. Lett. 112, 121102 (2014).

Already in the beginning of my research stay at UC Berkeley in the group of Prof. Holger Müller we realized that it is more applicable to build a Cesium atom interferometer in an optical cavity. Cesium is compared to Lithium easier to cool with laser light and magnetic fields. Instead of the proposed complicated laser system we were using standard diode laser which were afterward amplified in an optical cavity. This allowed us to measure any kind of interaction which highest precision using atom interferometric methods. With the amplified laser light, we were able to split, redirect and recombine the atomic wavefunction of Cesium atoms. In our case we used in each experimental run up to 1 million Cesium atoms. By determining the ratio of the two output ports of the interferometer and averaging our measurements we reached a sensitivity to accelerations of about 25 nm/s. This allowed us to sense the gravitational acceleration of a 0.19 kg in-vacuum source mass, which is around 10 times weaker than Earths gravity and we reached the natural scale for a wide class of cosmologically motivated scalar fields and improved our constraints on these dark energy motivated scalar field theories over several orders of magnitude. Within the last year at UC Berkeley we experimentally observed an attractive force on atoms due to blackbody radiation using atom interferometry techniques. This force-exerting property of blackbody radiation was quite surprising to the community, since it may affect the ultimate accuracy of atom interferometric metrology. Top publications: Atom-interferometry constraints on dark energy P. Hamilton, M. Jaffe, P. Haslinger, Q. Simmons, H. Müller, and J. Khoury Science 349, 849 (2015) arXiv:1502.03888 Testing sub-gravitational forces on atoms from a miniature in-vacuum source mass Matt Jaffe*, Philipp Haslinger*, Viktoria Xu, Paul Hamilton, Amol Upadhye, Benjamin Elder, Justin Khoury, Holger Müller *co-first authors Nature Physics, 13, 938-942 (2017) arXiv:1612.05171 Attractive force on atoms due to blackbody radiation Philipp Haslinger, Matt Jaffe, Victoria Xu, Osip Schwartz, Matthias Sonnleitner, Monika Ritsch-Marte, Helmut Ritsch, Holger Müller Nature Physics, 14, 257-260 (2018) arXiv:1704.03577