Derek F. Jackson Kimball

The Cosmic Axion Spin Precession Experiment (CASPEr): a dark-matter search with nuclear magnetic resonance

The Cosmic Axion Spin Precession Experiment (CASPEr) is a nuclear magnetic resonance experiment (NMR) seeking to detect axion and axion-like particles which could make up the dark matter present in the universe. We review the predicted couplings of axions and axion-like particles with baryonic matter that enable their detection via NMR. We then describe two measurement schemes being implemented in CASPEr. The first method, presented in the original CASPEr proposal, consists of a resonant search via continuous-wave NMR spectroscopy. This method offers the highest sensitivity for frequencies ranging from a few Hz to hundreds of MHz, corresponding to masses

A dual-isotope rubidium comagnetometer to search for anomalous long-range spin-mass (spin-gravity) couplings of the proton

m_{\rm a} \sim 10^{-14}

Constraints on long-range spin-gravity and monopole-dipole couplings of the proton

--

Surface coatings for atomic magnetometry

10^{-6}

Searching for dark matter with nuclear magnetic resonance : the Cosmic Axion Spin Precession Experiment

eV. Sub-Hz frequencies are typically difficult to probe with NMR due to the diminishing sensitivity of magnetometers in this region. To circumvent this limitation, we suggest new detection and data processing modalities. We describe a non-resonant frequency-modulation detection scheme, enabling searches from mHz to Hz frequencies (

A Precessing Ferromagnetic Needle Magnetometer

m_{\rm a} \sim 10^{-17}

Dynamics of a Ferromagnetic Particle Levitated Over a Superconductor.

--

Ellipticity-induced nonlinear magneto-optical rotation of frequency-modulated light

10^{-14}

Search for a coupling of the proton spin to gravity

eV), extending the detection bandwidth by three decades.

Optical magnetometer with probe and pump beams

The experimental concept of a search for a long-range coupling between rubidium (Rb) nuclear spins and the mass of the Earth is described. The experiment is based on simultaneous measurement of the spin precession frequencies for overlapping ensembles of 85Rb and 87Rb atoms contained within an evacuated, antirelaxation-coated vapor cell. Rubidium atoms are spin-polarized in the presence of an applied magnetic field by synchronous optical pumping with circularly polarized laser light. Spin precession is probed by measuring optical rotation of far-off-resonant, linearly polarized laser light. Simultaneous measurement of 85Rb and 87Rb spin precession frequencies enables suppression of magnetic-field-related systematic effects. The nuclear structure of the Rb isotopes makes the experiment particularly sensitive to anomalous spin-dependent interactions of the proton. Experimental sensitivity and a variety of systematic effects are discussed, and initial data are presented.