arXiv subjects

A. Wickenbrock

Publications and source records attributed to A. Wickenbrock.

10 recordsLinked to original sources

arXiv2025

A Multi-Messenger Search for Exotic Field Emission with a Global Magnetometer Network

Quantum sensor networks in combination with traditional astronomical observations are emerging as a novel modality for multi-messenger astronomy. Here we develop a generic analysis framework that uses a data-driven approach to model the sensitivity of a quantum sensor network to astrophysical signals as a consequence of beyond-the-Standard Model (BSM) physics. The analysis method evaluates correlations between sensors to search for BSM signals coincident with astrophysical triggers such as black hole mergers, supernovae, or fast radio bursts. Complementary to astroparticle approaches that search for particlelike signals (e.g. WIMPs), quantum sensors are sensitive to wavelike signals from exotic quantum fields. This analysis method can be applied to networks of different types of quantum sensors, such as atomic clocks, matter-wave interferometers, and nuclear clocks, which can probe many types of interactions between BSM fields and standard model particles. We use this analysis method to carry out the first direct search utilizing a terrestrial network of precision quantum sensors for BSM fields emitted during a black hole merger. Specifically we use the Global Network of Optical Magnetometers for Exotic physics (GNOME) to perform a search for exotic low-mass field (ELF) bursts generated in coincidence with a gravitational wave signal from a binary black hole merger (GW200311 115853) detected by LIGO/Virgo on the 11th of March 2020. The associated gravitational wave heralds the arrival of the ELF burst that interacts with the spins of fermions in the magnetometers. This enables GNOME to serve as a tool for multi-messenger astronomy. Our search found no significant events, and consequently we place the first lab-based limits on combinations of ELF production and coupling parameters.

astro-ph.HE↗

arXiv2023

What can a GNOME do? Search targets for the Global Network of Optical Magnetometers for Exotic physics searches

Numerous observations suggest that there exist undiscovered beyond-the-Standard-Model particles and fields. Because of their unknown nature, these exotic particles and fields could interact with Standard Model particles in many different ways and assume a variety of possible configurations. Here we present an overview of the Global Network of Optical Magnetometers for Exotic physics searches (GNOME), our ongoing experimental program designed to test a wide range of exotic physics scenarios. The GNOME experiment utilizes a worldwide network of shielded atomic magnetometers (and, more recently, comagnetometers) to search for spatially and temporally correlated signals due to torques on atomic spins from exotic fields of astrophysical origin. We survey the temporal characteristics of a variety of possible signals currently under investigation such as those from topological defect dark matter (axion-like particle domain walls), axion-like particle stars, solitons of complex-valued scalar fields (Q-balls), stochastic fluctuations of bosonic dark matter fields, a solar axion-like particle halo, and bursts of ultralight bosonic fields produced by cataclysmic astrophysical events such as binary black hole mergers.

hep-ph↗

arXiv2020

Atomic and molecular transitions induced by axions via oscillating nuclear moments

The interaction of standard model's particles with the axionic Dark Matter field may generate oscillating nuclear electric dipole moments (EDMs), oscillating nuclear Schiff moments and oscillating nuclear magnetic quadrupole moments (MQMs) with a frequency corresponding to the axion's Compton frequency. Within an atom or a molecule an oscillating EDM, Schiff moment or MQM can drive transitions between atomic or molecular states. The excitation events can be detected, for example, via subsequent fluorescence or photoionization. Here we calculate the rates of such transitions. If the nucleus has octupole deformation or quadrupole deformation then the transition rate due to Schiff moment and MQM can be up to $10^{-16}$ transition per molecule per year. In addition, an MQM-induced transition may be of M2-type, which is useful for the elimination of background noise since M2-type transitions are suppressed for photons.

hep-ph↗

arXiv2018

Overview of the Cosmic Axion Spin Precession Experiment (CASPEr)

An overview of our experimental program to search for axion and axion-like-particle (ALP) dark matter using nuclear magnetic resonance (NMR) techniques is presented. An oscillating axion field can exert a time-varying torque on nuclear spins either directly or via generation of an oscillating nuclear electric dipole moment (EDM). Magnetic resonance techniques can be used to detect such an effect. The first-stage experiments explore many decades of ALP parameter space beyond the current astrophysical and laboratory bounds. It is anticipated that future versions of the experiments will be sensitive to the axions associated with quantum chromodynamics (QCD) having masses $\lesssim 10^{-9}~{\rm eV}/c^2$.

physics.ins-det↗

arXiv2018

Characterization of the Global Network of Optical Magnetometers to search for Exotic Physics (GNOME)

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 dark-matter objects (for example, axion stars and domain walls). Properties of the GNOME sensors such as sensitivity, bandwidth, and noise characteristics are studied in the present work, and features of the network's operation (e.g., data acquisition, format, storage, and diagnostics) are described. Characterization of the GNOME is a key prerequisite to searches for and identification of exotic physics signatures.

physics.ins-det↗

arXiv2017

Network of sensitive magnetometers for urban studies

The magnetic signature of an urban environment is investigated using a geographically distributed network of fluxgate magnetometers deployed in and around Berkeley, California. The system hardware and software are described and results from initial operation of the network are reported. The sensors sample the vector magnetic field with a 4 kHz resolution and are sensitive to fluctuations below 0.1 $\textrm{nT}/\sqrt{\textrm{Hz}}$. Data from separate stations are synchronized to around $\pm100$ $μ{s}$ using GPS and computer system clocks. Data from all sensors are automatically uploaded to a central server. Anomalous events, such as lightning strikes, have been observed. A wavelet analysis is used to study observations over a wide range of temporal scales up to daily variations that show strong differences between weekend and weekdays. The Bay Area Rapid Transit (BART) is identified as the most dominant signal from these observations and a superposed epoch analysis is used to study and extract the BART signal. Initial results of the correlation between sensors are also presented.

physics.ins-det↗

arXiv2017

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

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 for a range of masses and radii not ruled out by existing observations, the terrestrial encounter rate with axion stars or Q-balls can be sufficiently high (at least once per year) for a detection. Furthermore, it is shown that a global network of atomic magnetometers is sufficiently sensitive to pseudoscalar couplings to atomic spins so that a transit through an axion star or Q-ball could be detected over a broad range of unexplored parameter space.

physics.atom-ph↗

arXiv2011

Vibrational mechanics in an optical lattice: controlling transport via potential renormalization

We demonstrate theoretically and experimentally the phenomenon of vibrational resonance in a periodic potential, using cold atoms in an optical lattice as a model system. A high-frequency (HF) drive, with frequency much larger than any characteristic frequency of the system, is applied by phase-modulating one of the lattice beams. We show that the HF drive leads to the renormalization of the potential. We used transport measurements as a probe of the potential renormalization. The very same experiments also demonstrate that transport can be controlled by the HF drive via potential renormalization.

cond-mat.stat-mech↗

arXiv2011

Current reversals in a rocking ratchet: the frequency domain

Motivated by recent work [D. Cubero et al., Phys. Rev. E 82, 041116 (2010)], we examine the mechanisms which determine current reversals in rocking ratchets as observed by varying the frequency of the drive. We found that a class of these current reversals in the frequency domain are precisely determined by dissipation-induced symmetry breaking. Our experimental and theoretical work thus extends and generalizes the previously identified relationship between dynamical and symmetry-breaking mechanisms in the generation of current reversals.

cond-mat.stat-mech↗

arXiv2011

Collective strong coupling in a lossy optical cavity

We observe vacuum Rabi splitting in a lossy nearly confocal cavity indicating the strong coupling regime, despite a weak single-atom single-mode coupling. Strong collective interaction manifests itself in the typical $\sqrt{N}$-dependence of the normal mode splitting on the number of atoms $N$. The $TEM_{00}$-mode coupling parameters are $(g,κ,γ)=2π\times(0.12,0.8,2.6)$ MHz and up to $(1.33\pm 0.08)\times10^5$ cesium atoms were loaded into the mode volume.

cond-mat.quant-gas↗