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

Characterization of the global network of optical magnetometers to search for exotic physics (GNOME)

Afach, S. ; Budker, D. ; Camp, G. De ; Dumont, V. ; Grujić, Zoran Dragan ; Guo, H. ; Jackson Kimball, D. F. ; Kornack, T. W. ; Lebedev, Victor ; Li, W. ; Masia-Roig, H. ; Nix, S. ; Padniuk, M. ; Palm, C. A. ; Pankow, C. ; Penaflor, A. ; Peng, X. ; Pustelny, Simon ; Scholtes, Theo ; Smiga, J. A. ; Stalnaker, J. E. ; Weis, Antoine ; Wickenbrock, A. ; Wurm, D.

In: Physics of the Dark Universe, 2018, vol. 22, p. 162–180

The Global Network of Optical Magnetometers to search for Exotic physics (GNOME) is a network of geographically separated, time-synchronized, optically pumped atomic magnetometers that is being used to search for correlated transient signals heralding exotic physics. The GNOME is sensitive to nuclear- and electron-spin couplings to exotic fields from astrophysical sources such as compact...

Université de Fribourg

Cesium alignment produced by pumping with unpolarized light

Shi, Yongqi ; Weis, Antoine

In: The European Physical Journal D, 2018, vol. 72, no. 4, p. 73

We demonstrate optical pumping on the four hyperfine components of the Cs D1 transition by unpolarized (UPL) resonant laser light. The evidence is based on the reduction of the absorption coefficients κ0 with increasing light power P in an uncoated Cs vapor cell with isotropic spin relaxation. For comparison we perform the same quantitative κ0(P) measurements with linearly-polarized light...

Université de Fribourg

Quantitative study of optical pumping in the presence of spin-exchange relaxation

Shi, Yongqi ; Scholtes, Theo ; Grujić, Zoran D. ; Lebedev, Victor ; Dolgovskiy, Vladimir ; Weis, Antoine

In: Physical Review A, 2018, vol. 97, no. 1, p. 013419

We have performed quantitative measurements of the variation of the on-resonance absorption coefficients κ0 of the four hyperfine components of the Cs D1 transition as a function of laser power P, for pumping with linearly and with circularly polarized light. Sublevel populations derived from rate equations assuming isotropic population relaxation (at a rate γ1) yield algebraic κ0(P)...

Université de Fribourg

Study of ³He Rabi nutations by optically-pumped cesium magnetometers

Koch, Hans-Christian ; Bison, Georg ; Grujiæ, Zoran Dragan ; Heil, Werner ; Kasprzak, Malgorzata ; Knowles, Paul ; Kraft, Andreas ; Pazgalev, Anatoly ; Schnabel, Allard ; Voigt, Jens ; Weis, Antoine

In: The European Physical Journal D, 2017, vol. 71, no. 10, p. 262

We describe a method for recording the Rabi nutation of nuclear spin polarized ³He by optically pumped cesium magnetometers. The measurement is performed by detecting the time-dependent magnetic field produced by the 3He magnetization. The observed signals are compared to theoretical models and the results are used to precisely trace the evolution of the magnetization. This procedure...

Université de Fribourg

Comment on: Magnetic field measurements in Rb vapor by splitting Hanle resonances under the presence of a perpendicular scanning magnetic field

Weis, Antoine ; Shi, Yongqi ; Grujić, Zoran D.

In: The European Physical Journal D, 2017, vol. 71, no. 4, p. 80

In a recent article in this journal Grewal and Pattabiraman reported on the splitting of ground state Hanle resonances (recorded with linearly polarized light) by a transverse field. They claimed a “linearly proportional” dependence on the transverse field strength and supported this observation with results from numerical simulations. In this comment we argue that the splitting occurs...

Université de Fribourg

Orientational dependence of optically detected magnetic resonance signals in laser-driven atomic magnetometers

Colombo, Simone ; Dolgovskiy, Vladimir ; Scholtes, Theo ; Grujić, Zoran D. ; Lebedev, Victor ; Weis, Antoine

In: Applied Physics B, 2017, vol. 123, no. 1, p. 35

We have investigated the dependence of lock-in-demodulated Mx-magnetometer signals on the orientation of the static magnetic field B0 of interest. Magnetic resonance spectra for 2400 discrete orientations of B0 covering a 4π solid angle have been recorded by a PC-controlled steering and data acquisition system. Off-line fits by previously derived lineshape functions allow us to extract the...

Université de Fribourg

Investigation of the intrinsic sensitivity of a ³He/Cs magnetometer

Koch, Hans Christian ; Bison, Georg ; Grujić, Zoran D. ; Heil, Werner ; Kasprzak, Malgorzata ; Knowles, Paul ; Kraft, Andreas ; Pazgalev, Anatoly ; Schnabel, Allard ; Voigt, Jens ; Weis, Antoine

In: The European Physical Journal D, 2015, vol. 69, no. 11, p. 1–11

We report on extensive studies on the intrinsic sensitivity of a combined ³He/Cs magnetometer. The magnetometer relies on the detection of the free spin precession of nuclear spin polarized ³He by optically pumped cesium magnetometers. We characterize the relevant processes involved in the detection and quantify their impact on the total sensitivity of the magnetometer. An expression is derived...