The Geraci group employs high-Q resonant sensors for ultra-sensitive force and field detection in searches for new physics beyond the Standard Model. Key thrusts: (1) Optically-trapped levitated dielectric nanospheres and microspheres achieving zeptonewton (10⁻²¹ N) force sensitivity, applied to probing short-range deviations from Newtonian gravity at micrometer scales; (2) ARIADNE, an international NMR-based experiment using superfluid ³He to search for the QCD axion via axion-mediated spin-dependent forces between a rotating mass and polarized nuclei; (3) Collaboration on MAGIS-100, the 100 m-tall atom interferometer at Fermilab for gravitational wave detection in the mid-band (0.3–10 Hz) and ultralight dark matter searches; (4) Cryogenic optical cavity dark matter comparisons with Gabrielse and Kovachy groups. Member of CFP Northwestern and CIERA. APS Francis M. Pipkin Award 2023.
Kapitulnik combines cryogenic scanning-SQUID and Sagnac magneto-optic Kerr microscopy of unconventional and topological superconductors with high-precision torsion-balance experiments that test Newtonian gravity at short range and search for exotic spin-dependent forces, spanning table-top tests of fundamental physics and quantum materials characterization.
The Kovachy Group applies quantum wave properties of ultracold atoms to precision sensing. Primary focus: (1) Advanced large-momentum-transfer (LMT) atom interferometer pulse sequences using Bragg diffraction and Bloch oscillations to achieve record momentum splits of 100s of ℏk, enhancing sensitivity for fundamental physics tests; (2) MAGIS-100 collaboration — the 100 m-tall atom interferometer at Fermilab targeting gravitational waves in the mid-band complementary to LIGO/LISA, dark matter field searches, and tests of quantum mechanics at macroscopic scales; (3) Search for deviations from Newtonian gravity at micrometer range using atom-interferometric force sensing, and a new measurement of Newton's gravitational constant G; (4) Cryogenic optical cavity dark matter search (with Gabrielse and Geraci groups). David and Lucile Packard Fellow (2020), Paul Ehrenfest Best Paper Award 2020, NIST Precision Measurement Grant 2019. Member of CFP Northwestern and CIERA.
Hendrik Ulbricht's group pioneers levitated optomechanics and macroscopic quantum systems. Research: (1) optical levitation of nanoparticles for zeptonewton force sensing and quantum-to-classical transition tests; (2) magnetic levitation of micromagnets (diamagnetically stabilised) as ultralight dark matter detectors and magnetometers (fT/√Hz sensitivity demonstrated with LeMaMa levitated ferromagnet); (3) spin entanglement witness for quantum gravity (BMV experiment — levitated diamond with NV centre); (4) tests of the Diósi-Penrose model of wavefunction collapse. Multiple Reviews of Modern Physics; active in macroscopic quantum physics community.