Université de Fribourg

Analysis method for detecting topological defect dark matter with a global magnetometer network

Masia-Roig, Hector ; A.Smiga, Joseph ; Budker, Dmitry ; Dumont, Vincent ; Gruji, Zoran ; Kim, Dongok ; Kimball, Derek F. Jackson ; Lebedev, Victor ; Monroy, Madeline ; Pustelny, Szymon ; Scholtes, Theo ; Segura, Perrin C. ; Semertzidi, Yannis K. ; Shin, Yun Chang ; Stalnaker, Jason E. ; Sulai, Ibrahim ; Weis, Antoine ; Wickenbrock, Arne

In: Physics of the Dark Universe, 2020, vol. 28, p. 100494

The Global Network of Optical Magnetometers for Exotic physics searches (GNOME) is a network of time-synchronized, geographically separated, optically pumped atomic magnetometers that is being used to search for correlated transient signals heralding exotic physics. GNOME is sensitive to exotic couplings of atomic spins to certain classes of dark matter candidates, such as axions. This work...

Université de Fribourg

Searching for axion stars and $Q$-balls with a terrestrial magnetometer network

Kimball, D. F. Jackson ; Budker, D. ; Eby, J. ; Pospelov, M. ; Pustelny, Szymon ; Scholtes, Theo ; Stadnik, Y. V. ; Weis, Antoine ; Wickenbrock, A.

In: Physical Review D, 2018, vol. 97, no. 4, p. 043002

Light (pseudo-)scalar fields are promising candidates to be the dark matter in the Universe. Under certain initial conditions in the early Universe and/or with certain types of self-interactions, they can form compact dark-matter objects such as axion stars or Q-balls. Direct encounters with such objects can be searched for by using a global network of atomic magnetometers. It is shown that...

Université de Fribourg

Suppression of spin-exchange relaxation in tilted magnetic fields within the geophysical range

Scholtes, Theo ; Pustelny, Szymon ; Fritzsche, Stephan ; Schultze, Volkmar ; Stolz, Ronny ; Meyer, Hans-Georg

In: Physical Review A, 2016, vol. 94, no. 1, p. 13403

We present a detailed experimental and theoretical study on the relaxation of spin coherence due to the spin-exchange mechanism arising in the electronic ground states of alkali-metal vapor atoms. As opposed to the well-explored formation of a stretched state in a longitudinal geometry (magnetic field parallel to the laser propagation direction) we employ adapted hyperfine-selective optical...