arXiv subjects

David C. Moore

Publications and source records attributed to David C. Moore.

33 records · Page 2Linked to original sources

arXiv2021

Trapped electrons and ions as particle detectors

Electrons and ions trapped with electromagnetic fields have long served as important high-precision metrological instruments, and more recently have also been proposed as a platform for quantum information processing. Here we point out that these systems can also be used as highly sensitive detectors of passing charged particles, due to the combination of their extreme charge-to-mass ratio and low-noise quantum readout and control. In particular, these systems can be used to detect energy depositions many orders of magnitude below typical ionization scales. As illustrations, we suggest some applications in particle physics. We outline a non-destructive time-of-flight measurement capable of sub-eV energy resolution for slowly moving, collimated particles. We also show that current devices can be used to provide competitive sensitivity to models where ambient dark matter particles carry small electric millicharges $\ll e$. Our calculations may also be useful in the characterization of noise in quantum computers coming from backgrounds of charged particles.

quant-ph↗

arXiv2021

Limits on the abundance of millicharged particles bound to matter

Millicharged particles (mCPs) are hypothesized particles possessing an electric charge that is a fraction of the charge of the electron. We report a search for mCPs with charges $\gtrsim 10^{-4}~e$ that improves sensitivity to their abundance in matter by roughly two orders of magnitude relative to previous searches. This search is sensitive to such particles over a wide range of masses and charges for which they can form stable bound states with matter, corresponding to a gap in parameter space that is beyond the reach of previous searches from accelerators, colliders, cosmic-ray experiments, and cosmological constraints.

hep-ex↗

arXiv2021

Searching for new physics using optically levitated sensors

We describe a variety of searches for new physics beyond the Standard Model of particle physics which may be enabled in the coming years by the use of optically levitated masses in high vacuum. Such systems are expected to reach force and acceleration sensitivities approaching (and possibly eventually exceeding) the standard quantum limit over the next decade. For new forces or phenomena that couple to mass, high precision sensing using objects with masses in the fg-ng range have significant discovery potential for new physics. Such applications include tests of fundamental force laws, searches for non-neutrality of matter, high-frequency gravitational wave detectors, dark matter searches, and tests of quantum foundations using massive objects.

quant-ph↗

arXiv2020

Search for composite dark matter with optically levitated sensors

Results are reported from a search for a class of composite dark matter models with feeble, long-range interactions with normal matter. We search for impulses arising from passing dark matter particles by monitoring the mechanical motion of an optically levitated nanogram mass over the course of several days. Assuming such particles constitute the dominant component of dark matter, this search places upper limits on their interaction with neutrons of $α_n \leq 1.2 \times 10^{-7}$ at 95\% confidence for dark matter masses between 1--10 TeV and mediator masses $m_ϕ\leq 0.1$ eV. Due to the large enhancement of the cross-section for dark matter to coherently scatter from a nanogram mass ($\sim 10^{29}$ times that for a single neutron) and the ability to detect momentum transfers as small as $\sim$200 MeV/c, these results provide sensitivity to certain classes of composite dark matter models that substantially exceeds existing searches, including those employing kg-scale or ton-scale targets. Extensions of these techniques can enable directionally-sensitive searches for a broad class of previously inaccessible heavy dark matter candidates.

hep-ex↗

arXiv2020

Mechanical Quantum Sensing in the Search for Dark Matter

Numerous astrophysical and cosmological observations are best explained by the existence of dark matter, a mass density which interacts only very weakly with visible, baryonic matter. Searching for the extremely weak signals produced by this dark matter strongly motivate the development of new, ultra-sensitive detector technologies. Paradigmatic advances in the control and readout of massive mechanical systems, in both the classical and quantum regimes, have enabled unprecedented levels of sensitivity. In this white paper, we outline recent ideas in the potential use of a range of solid-state mechanical sensing technologies to aid in the search for dark matter in a number of energy scales and with a variety of coupling mechanisms.

physics.ins-det↗

arXiv2020

Force and acceleration sensing with optically levitated nanogram masses at microkelvin temperatures

This paper demonstrates cooling of the center-of-mass motion of 10 $μ$m-diameter optically levitated silica spheres to an effective temperature of $50\pm22 μ$K, achieved by minimizing the technical pointing noise of the trapping laser. This low noise leads to an acceleration and force sensitivity of $95\pm41$ n$g/\sqrt{\mathrm{Hz}}$ ($g = 9.8$ m/s$^2$) and $0.95\pm0.11$ aN$/\sqrt{\mathrm{Hz}}$, respectively, at frequencies near 50 Hz. This force sensitivity is comparable to that demonstrated for optically levitated nanospheres that are $10^4$ times less massive, corresponding to an acceleration sensitivity that is several orders of magnitude better. It is further shown that under these conditions the spheres remain stably trapped at pressures of $\sim 10^{-7}$ mbar with no active cooling for periods longer than a day. Feedback cooling is still necessary in the moderate-pressure regime, motivating a comprehensive study of the loss mechanisms of the microspheres and providing better understanding of the requirements for feedback-free optical trapping in vacuum. This work can enable high-sensitivity searches for accelerations and forces acting on micron-sized masses, including those that could be produced by new physics beyond the Standard Model.

physics.optics↗

arXiv2018

Optical levitation of 10 nanogram spheres with nano-$g$ acceleration sensitivity

We demonstrate optical levitation of SiO$_2$ spheres with masses ranging from 0.1 to 30 nanograms. In high vacuum, we observe that the measured acceleration sensitivity improves for larger masses and obtain a sensitivity of $0.4 \times 10^{-6}\ g/\sqrt{\mathrm{Hz}}$ for a 12 ng sphere, more than an order of magnitude better than previously reported for optically levitated masses. In addition, these techniques permit long integration times and a mean acceleration of $(-0.7\pm2.4\,[stat] \pm 0.2\,[syst])\times ~ 10^{-9}\,g$ is measured in $1.4\times 10^4$~s. Spheres larger than 10~ng are found to lose mass in high vacuum where heating due to absorption of the trapping laser dominates radiative cooling. This absorption constrains the maximum size of spheres that can be levitated and allows a measurement of the absorption of the trapping light for the commercially available spheres tested here. Spheres consisting of material with lower absorption may allow larger objects to be optically levitated in high vacuum.

physics.optics↗

arXiv2018

Optical Rotation of Levitated Spheres in High Vacuum

A circularly polarized laser beam is used to levitate and control the rotation of microspheres in high vacuum. At low pressure, rotation frequencies as high as 6 MHz are observed for birefringent vaterite spheres, limited by centrifugal stresses. Due to the extremely low damping in high vacuum, controlled optical rotation of amorphous SiO$_2$ spheres is also observed at rates above several MHz. At $10^{-7}$ mbar, a damping time of $6\times10^4$ s is measured for a $10\ μ$m diameter SiO$_2$ sphere. No additional damping mechanisms are observed above gas damping, indicating that even longer damping times may be possible with operation at lower pressure. The controlled optical rotation of microspheres at MHz frequencies with low damping, including for materials that are not intrinsically birefringent, provides a new tool for performing precision measurements using optically levitated systems.

physics.optics↗

arXiv2018

Single-beam dielectric-microsphere trapping with optical heterodyne detection

A technique to levitate and measure the three-dimensional position of micrometer-sized dielectric spheres with heterodyne detection is presented. The two radial degrees of freedom are measured by interfering light transmitted through the microsphere with a reference wavefront, while the axial degree of freedom is measured from the phase of the light reflected from the surface of the microsphere. This method pairs the simplicity and accessibility of single beam optical traps to a measurement of displacement that is intrinsically calibrated by the wavelength of the trapping light and has exceptional immunity to stray light. A theoretical shot noise limit of $1.3\times10^{-13}\,\text{m}/\sqrt{\text{Hz}}$ for the radial degrees of freedom, and $3.0\times10^{-15} \, \text{m}/\sqrt{\text{Hz}}$ for the axial degree of freedom can be obtained in the system described. The measured acceleration noise in the radial direction is $7.5\times10^{-5} \, (\text{m/s}^2)/\sqrt{\text{Hz}}$.

physics.ins-det↗

arXiv2016

Search for Screened Interactions Associated with Dark Energy Below the 100 $\mathrm{μm}$ Length Scale

We present the results of a search for unknown interactions that couple to mass between an optically levitated microsphere and a gold-coated silicon cantilever. The scale and geometry of the apparatus enables a search for new forces that appear at distances below 100 $μ$m and which would have evaded previous searches due to screening mechanisms. The data are consistent with electrostatic backgrounds and place upper limits on the strength of new interactions at $<0.1$ fN in the geometry tested. For the specific example of a chameleon interaction with an inverse power law potential, these results exclude matter couplings $β> 5.6 \times 10^4$ in the region of parameter space where the self-coupling $Λ\gtrsim 5$ meV and the microspheres are not fully screened.

hep-ex↗

arXiv2014

Search for Millicharged Particles Using Optically Levitated Microspheres

We report results from a search for stable particles with charge > $10^{-5}$ e in bulk matter using levitated dielectric microspheres in high vacuum. No evidence for such particles was found in a total sample of 1.4 ng, providing an upper limit on the abundance per nucleon of 2.5 x $10^{-14}$ at the 95% confidence level for the material tested. These results provide the first direct search for single particles with charge < 0.1 e bound in macroscopic quantities of matter and demonstrate the ability to perform sensitive force measurements using optically levitated microspheres in vacuum.

hep-ex↗

arXiv2010

Titanium Nitride Films for Ultrasensitive Microresonator Detectors

Titanium nitride (TiNx) films are ideal for use in superconducting microresonator detectors because: a) the critical temperature varies with composition (0 < Tc < 5 K); b) the normal-state resistivity is large, ρ_n ~ 100 $μ$Ohm cm, facilitating efficient photon absorption and providing a large kinetic inductance and detector responsivity; and c) TiN films are very hard and mechanically robust. Resonators using reactively sputtered TiN films show remarkably low loss (Q_i > 10^7) and have noise properties similar to resonators made using other materials, while the quasiparticle lifetimes are reasonably long, 10-200 $μ$s. TiN microresonators should therefore reach sensitivities well below 10^-19 WHz^(-1/2).

cond-mat.supr-con↗

arXiv2006

The Effect of Reduced Spatial Symmetries on Lattice States: Results for Non-zero Linear Momentum

The irreducible representations of the cubic space group are described and used to determine the mapping of continuum states to lattice states with non-zero linear momentum. The Clebsch-Gordan decomposition is calculated from the character table for the cubic space group. These results are used to identify multiparticle states which appear in the hadron spectrum on the lattice.

hep-lat↗

arXiv2006

Angular Momentum on the Lattice: The Case of Non-Zero Linear Momentum

The irreducible representations (IRs) of the double cover of the Euclidean group with parity in three dimensions are subduced to the corresponding cubic space group. The reduction of these representations gives the mapping of continuum angular momentum states to the lattice in the case of non-zero linear momentum. The continuous states correspond to lattice states with the same momentum and continuum rotational quantum numbers decompose into those of the IRs of the little group of the momentum vector on the lattice. The inverse mapping indicates degeneracies that will appear between levels of different lattice IRs in the continuum limit, recovering the continuum angular momentum multiplets. An example of this inverse mapping is given for the case of the ``moving'' isotropic harmonic oscillator.

hep-lat↗

arXiv2006

Multiparticle States and the Hadron Spectrum on the Lattice

The Clebsch-Gordan decomposition is calculated for direct products of the irreducible representations of the cubic space group. These results are used to identify multiparticle states which appear in the hadron spectrum on the lattice. Consideration of the cubic space group indicates how combinations of both zero momentum and non-zero momentum multiparticle states contribute to the spectrum.

hep-lat↗