Optomechanical Sensing for Subatomic and Astroparticle Physics

23 Sept 2026, 08:00 → 25 Sept 2026, 13:30 Canada/Eastern

Kyle Leach (Colorado School of Mines)

WORKSHOP FOCUS

The meeting will connect researchers developing state-of-the-art optomechanical sensors in the nuclear, particle, and astroparticle communities that could use them. A central goal is to identify concrete experimental opportunities, technical challenges, and new collaborations at the interface of these fields.

CONTEXT: OPTOMECHANICAL SENSING

Mechanical resonators operating at or near the quantum limit are opening new approaches to some of the most challenging measurements in fundamental physics. This workshop will bring together researchers in optomechanics, quantum sensing, atomic physics, and subatomic and astroparticle physics to explore how these rapidly developing technologies can be applied to searches for new particles and forces, precision recoil measurements, neutrino physics, dark matter detection, and tests of fundamental quantum mechanics.

TOPICS

- Levitated and cavity optomechanical sensors

- Quantum-limited force, impulse, and acceleration measurements

- Dark matter and new-force searches

- Nuclear decays, recoils, and neutrino measurements

- Tests of quantum mechanics and gravity

- Sensor control, readout, backgrounds, and scalability

FORMAT
Invited and contributed presentations, focused discussion sessions, and opportunities for informal scientific exchange and collaboration. Remote participation may be permitted by request. Please see the Registration page to request remote access, or other accommodation needs that would address barriers to your participation.

 

TRAVEL TO KINGSTON

People in Toronto, Montreal, or Ottawa can travel to Kingston by driving, or by Via Rail or bus options such as Megabus and Flixbus. 

 

If you are travelling from further away, we recommend flying to Toronto Pearson International Airport or to Montreal Pierre Elliott Trudeau International Airport, and then traveling to Kingston as listed above. You could also fly to Syracuse or Watertown, NY and get a rental car to drive to Kingston.

 

However, if you are flying Air Canada, you can put Kingston's Norman Rogers Airport (YGK) as your final destination, which allows you to transfer at Pearson to the Landline Bus run by Air Canada. If you are flying with another airline, you can fly to Pearson, and then purchase a separate ticket on the Landline to Kingston (https://landline.com/canada/kingston).

 

Once in Kingston, you can travel via Uber, or by taxi with Amey's Taxi (613-546-1111) or Modern Taxi (613-546-2222).

 

Conference Schedule

See Timetable on the left menu, but a pdf of the current schedule is visible here: OSSAP_Schedule_at_a_Glance [pdf; 173 kB]

OSSAP_Schedule_20260920_Updated.pdf

Wednesday 23 September

08:00 Breakfast

Overview: Opening & Overview

Convener: Wouter Van De Pontseele (Colorado School of Mines)

1 Welcome

Speakers: Arthur McDonald, Kyle Leach (Queen's University)

2 Workshop logistics and practical information

Speaker: Wouter Van De Pontseele (Colorado School of Mines)

OSSAP2026_intro_Wouter.pdf

OSSAP2026_intro_Wouter.pptx

3 Overview of broad scope and theory

Motivation for optomechanical sensing across subatomic and astroparticle physics

Speaker: Zhen Liu

9_DM_Queens2026_v6ZL_trim.pdf

10:30 Coffee Break

Quantum Measurement, Gravity & Dark Matter: Morning

Convener: Wouter Van De Pontseele (Colorado School of Mines)

4 Quantum measurements of particles and of waves for probes of gravity: unconditional observation of quantum back-action on gravitational-wave detectors

Quantum measurement of the motion of particles originated in the study of gravitational-wave detectors. One part of the talk will motivate why and how further acceleration in our ability to measure motion can shed light on the nature of gravity. I will then describe the recent unconditional observation of quantum back-action on gravitational-wave detectors, realizing one of the long-standing theoretical predictions in quantum measurement theory. The second half of the talk will describe quantum enhancement in the measurement of waveforms and in generating clock signals, all of which expand the toolset at the frontier of quantum measurement science.

Speaker: Vivishek Sudhir (MIT)

5 Sensing gravitational waves and dark matter with superfluid helium: tunable acoustic Weber-bar resonators with cavity-electromechanical readout

Motivated by the seminal experiments of DeLorenzo and Schwab, along with theoretical predictions for coupling of acoustic resonators to dark matter, we have embarked on an effort to build small-scale detectors of gravitational waves and ultra-light dark matter using superfluid helium resonators. The core idea is to build a Weber bar, which resonantly enhances the strain signal from these sources, but with the added feature that at low-temperatures helium remains a liquid, enabling tuning of the acoustic resonance frequency. Coupled with the vanishing acoustic losses in the superfluid state of helium, this makes superfluid helium resonators the ideal acoustic detectors. Readout is performed using modern cavity electromechanics, furthering the toolbox of advanced techniques to measure and control these acoustic detectors.

Speaker: John Davis (University of Alberta)

12:05 Lunch

Quantum Measurement, Gravity & Dark Matter: Afternoon

Convener: Wouter Van De Pontseele (Colorado School of Mines)

6 Search for scalar ultralight dark matter using cryogenic optical cavities: first demonstration with two cryogenic sapphire Fabry–Pérot cavities

One of the biggest challenges in fundamental physics is understanding the microscopic nature of dark matter. Scalar ultralight dark matter (ULDM) is a well-motivated extension to the standard model (SM) of particle physics, hypothesized to couple to SM parameters like the electron mass and the fine-structure constant, thereby inducing coherent oscillations in the size of macroscopic solids at the ULDM Compton frequency.

This talk presents the first experimental demonstration of a novel optomechanical ULDM sensor that employs two cryogenic sapphire Fabry-Pérot optical cavities. This apparatus leverages the cavities' longitudinal mechanical resonances to achieve sensitivity to differential cavity length variations induced by ULDM.

A four-day observation period with this sensor achieved an improvement of up to two orders of magnitude in the limits to ULDM coupling to the SM for the ULDM’s Compton frequencies ranging from 5 kHz to 100 kHz. This was demonstrated for both the galactic halo and the Earth-bound relaxion halo models. This work represents a crucial step towards future upgrades, which are projected to yield an improvement of up to five orders of magnitude over a wider frequency range (100 Hz to 1 MHz), ultimately surpassing the theoretical naturalness threshold.

Speaker: Tejas Deshpande (Northwestern University)

Tejas_OSSAP_2026-09-23.pptx

7 Looking for dark photons with two-photon atomic transitions: coherent parahydrogen ensembles and the CATCHY pathfinder

Direct detection experiments for particle dark matter have grown to enormous target masses, yet conventional detectors' sensitivity scales only linearly with volume. Quantum-coherent detection schemes offer an alternative: by exploiting collective effects across a macroscopic ensemble, the signal itself can scale quadratically with size. I present the theoretical framework for one such approach, a dark photon search based on collective two-photon transitions in a coherent volume of parahydrogen, and describe CATCHY, its pathfinder experiment at Queen's University. (15+5)

Speaker: Andrew Buchanan (Queen's University)

CATCHYOSSAP.pdf

CATCHYOSSAP.pptx

8 Heavy Neutrino Experiment Using Levitated Tritiated Nanoparticles

(15+5)

Speaker: Samuele Sangiorgio (Lawrence Livermore National Laboratory)

sangiorgio_heavy_nu_tritiated_lnp.pdf

9 Trapping solid noble gases

(15+5)

Speaker: Lucas Darroch (Yale)

Noble Gas Optomechanical Sensors - compressed.pptx

Working Session: Free Discussion with Coffee

16:00 Dinner on Own

19:00 Conference Reception

Thursday 24 September

08:00 Breakfast

Overview: Modalities and Experiments

Convener: Joseph Formaggio

10 Overview of modalities and experiments

The experimental landscape of optomechanical sensors for fundamental physics

Speaker: David Moore (Yale University)

20260924_Queens.pdf

20260924_Queens.pptx

10:00 Coffee Break

Levitated Sensors: I - Levitated Optomechanics

Convener: Joseph Formaggio

11 Optomechanical sensors for gravity, dark matter, and axions: levitated tests of quantum gravity and high-frequency gravitational-wave searches

Optomechanical sensors have achieved impressive levels of sensitivity, advancing into the quantum-regime, limited by the measurement imprecision associated with photon shot noise or the quantum backaction from radiation pressure. Optically levitated particles exhibit extreme decoupling from the environment, making them excellent sensors of small forces, torques, or accelerations. In this talk, I will present recent experimental results on a search for ultralight scalar dark matter using cryogenic optical cavities. I will also discuss our progress towards using levitated optomechanical systems for tests of quantum effects related to gravity, and to search for high frequency gravitational waves and ultralight dark matter.

Speaker: Andrew Geraci

12 Gravitational-wave response of optically levitated sensors in Fabry–Pérot cavities: relativistic derivation and the input-mirror asymmetry

Optically levitated sensors inside a Fabry–Pérot cavity have been proposed for high-frequency gravitational-wave detection, but their optimal configuration exhibits a counterintuitive spatial asymmetry. We provide a fully relativistic derivation of the interaction between a gravitational wave and a levitated object in an optical cavity, demonstrating that the GW response is maximized when the sensor is located near the input mirror. We then explain this asymmetry from multiple gauge perspectives and highlight some important consequences for noise couplings in the experiment. Finally, we consider finite-sized dielectric sensors and show that even with modest dimensions, the dielectric can substantially modify the cavity fields, impacting both the optical trapping frequency and system transfer functions.

Speaker: Andrew Laeuger (Caltech)

Kingston Workshop Slides.pdf

Kingston Workshop Slides.pptx

13 A quantum-limited levitated force and recoil sensor: minimum-uncertainty nanoparticle states and sub-zero-point recoil detection

Nanomechanical oscillators are exciting sensing platforms with applications in both fundamental and applied research. One of their distinctive features is their ability to couple to a plethora of forces while operating with quantum-limited performance. An example of such a platform is an optically levitated nanoparticle in vacuum. Recently, we managed to prepare the motion of such a particle in minimum-uncertainty quantum states, which are relevant for sensing purposes. In this talk, I will present our recent work on measuring and controlling a levitated particle in the quantum regime. I will show how the nanoparticle can be operated both as a continuous force sensor and as a recoil sensor. Moreover, we realise a mechanical amplifier by exploiting quantum correlations between position and momentum. In this way, we are able to detect recoils even weaker than the momentum zero-point value. This remarkable sensitivity will also be crucial for preparing more exotic quantum states, such as a Schrödinger’s cat, by making the nanoparticle sensitive to weak nonlinear forces.

Speaker: Massimiliano Rossi (TU Delft)

talk_mr.pdf

12:15 Lunch

Levitated Sensors: II

Convener: David Moore (Yale University)

14 Low-noise levitated oscillators and calorimetry with levitated superconductors: chip-based magnetic traps and single nuclear-decay energy measurement

Optical tweezers have been at the forefront of technological advancement in levitated optomechanics and are still the only platform to cool spheres to the ground state of motion. However, they come with a major drawback of providing a back-action force that is difficult to reduce. Magnetic levitation offers an alternative that decouples the trapping from measurement allowing back-action free levitation. This technique could provide benefits when not detecting particle displacement with continuous weak measurement. Chip-based magnetic traps are a promising platform that allow for tighter trapping and the ability to scale up to arrays of traps. I will show the efforts of our group to levitate and control superconducting particles with these chip-based trap including inital work to scale to arrays of particles. I will also describe a scheme to measure the energy absorbed during a nuclear decay by the internal modes of a superconducting sphere levitated in a magnetic field. When the energy is absorbed, the subsequent increase in the temperature of the sphere will reduce its resonant frequency and alter its equilibrium position. By continuously tracking these properties, the energy deposited by a single nuclear decay can be measured. This could find uses in kinematic reconstruction of dark matter interactions or nuclear decays, characterisation of rare-isotopes and identification of the Mössbauer effect in new isotopes.

Speaker: Thomas Penny (Chalmers)

260924_OSSAP_LownoiseMicrocal.pptx

15 Magnetomechanics and levitation: laser-free Paul-trapped micromagnets coupled to superconducting circuits for quantum state preparation

Levitodynamics, where a mesoscopic particle is held in vacuum, provides a promising platform to study quantum mechanics in massive resonators. Yet, most approaches rely on the use of laser light to generate the trapping potential or measure/control the resonator, leading to bulk heating and limiting the type of object that can be levitated. Our approach leverages a Paul trap and magnetomechanical coupling to a superconducting circuit, hence removing the need for a laser. I will present our progress with the trapping at cryogenic temperatures of micron-sized magnets and their coupling to superconducting circuits. By coupling to circuits, this approach opens the circuit QED toolbox for QND measurements and quantum state preparation. Leveraging this, we propose to use this platform to prepare complex quantum states in massive mechanical resonators.

Speaker: Mathieu Juan (Université de Sherbrooke)

Presentation_Levitation_Kingston.pptx

14:50 Coffee Break

Quantum Measurement, Gravity & Dark Matter: Tethered Sensors & Particle Detection

Convener: David Moore (Yale University)

16 The Invisible Drummer: membrane optomechanical accelerometer search for ultralight dark photon dark matter, and the transition to phase II

Advances in cooling and probing of solid-state mechanical oscillators using optical cavities have spurred widespread interest in using cavity optomechanical systems as tabletop dark matter detectors [1]. I'll describe a demonstration experiment in which a cryogenically cooled silicon nitride membrane is used to search for coherently oscillating force fields produced by ultralight dark photon dark matter [2,3]. I'll also discuss progress towards building a quantum-enhanced array of such detectors by integrating them into a distributed squeezed-light network [4,5].

[1] Carney, et. al. "Mechanical quantum sensing in the search for dark matter." QSIT (2021). [2] Manley et. al. "Searching for vector dark matter with an optomechanical accelerometer." Phys. Rev. Lett. (2021). [3] Chowdhury et al. "Optomechanical accelerometer search for ultralight dark matter." Phys. Rev. D (2026). [4] Xia et al. "Entanglement-enhanced optomechanical sensing." Nat. Phot. (2023). [5] Brady et al. "Entanglement-enhanced optomechanical sensor array with application to dark matter searches." Comm. Phys. (2023).

Speaker: Dalziel Wilson (Arizona)

Kingston_2025_OMDM_v3.pptx

Kingston_2025_OMDM_v4.pptx

Working Session: Free Discussion

19:00 Dinner - The Merchant Tap House

Friday 25 September

08:00 Breakfast

Quantum Optomechanics & Particle Sensors

Convener: Daniel Carney (Berkeley National Lab)

17 Quantum Invisible Particle Sensor (QuIPS): recoil reconstruction of nuclear decays in a trapped nanosphere for sterile-neutrino searches

The QuIPS (Quantum Invisible Particle Sensor) experiment is an optomechanical laser trap surrounded by active particle detectors. It is designed to reconstruct the full momenta of weak nuclear decay products by combining the recoil impulse imparted to a trapped nanosphere, read out at the standard quantum limit, with a direct measurement of the emitted beta particle. This enables searches for heavy sterile neutrinos in the 100s of keV to few MeV range, as well as other BSM physics. I will give an overview of the project, including the electron detector we have built and its first calibration results, and present first designs for an optical levitation setup now being developed at LBL using 1550 nm trapping light. I will also briefly cover the status of the first recoil demonstration now underway at Yale, where nanospheres are being loaded with F-18. Finally, I will discuss what future searches will require on both fronts: sphere arrays and squeezed readout to push the impulse sensitivity, and improved efficiency and energy resolution on the particle detection side.

Speaker: Daniel Kodroff (Lawrence Berkeley National Lab)

18 Thermal-limited motion and optomechanical control of a levitated superfluid drop

Objects that are levitated in vacuum and coupled to an optical cavity have been used as high-performance optomechanical systems in a number of experiments. However, levitated objects are difficult to cool cryogenically and are highly susceptible to external heat loads. Here we show that a levitated drop of superfluid helium can serve as an optomechanical system that maintains sub-Kelvin internal temperature and noise temperature, even when illuminated by milliWatt-scale laser beams. The radiation pressure coupling between the drop's optical whispering gallery modes and its surface is demonstrated via the optical spring effect.

Speaker: Jack Harris (Yale)

10:20 Coffee Break

Working Session: Working Groups

Convener: Daniel Carney (Berkeley National Lab)

19 Working groups:

Focus: collaborative opportunities, outstanding challenges.

Speaker: Daniel Carney (Berkeley National Lab)

20 Breakout Groups

Small-group discussions on collaborative efforts and open challenges; each group prepares a short summary and candidate white-paper section:
1. Dark-matter targets and theory
2. Gravitational waves and tests of gravity
3. Nuclear decays, recoils and neutrinos
4. Readout, quantum control and shared technology

21 Report Back

Breakout leads report-back and plenary discussion.

Overview: Closing

Convener: Daniel Carney (Berkeley National Lab)

22 Conference Closing

Closing Remarks and Summary

Speaker: Kyle Leach (Queen's University)

12:45 Lunch