About

Tim Kovachy is an Assistant Professor in the Department of Physics and Astronomy at Northwestern University. He earned his PhD from Stanford University in 2016. His research focuses on atom interferometers that utilize the quantum mechanical wavelike properties of massive particles to make precise measurements of quantities such as accelerations and rotations. These measurements are valuable for fundamental physics tests and practical applications. In his group, Kovachy employs advanced atomic beam splitter and mirror techniques along with ultracold atoms to implement atom interferometers with enhanced sensitivity. His work includes searching for new physics beyond the Standard Model, such as deviations from the gravitational inverse square law, and developing improved quantum sensors. He is involved in projects to measure Newton's gravitational constant more accurately and to develop atomic gravitational sensors. Kovachy is a member of the MAGIS collaboration, which is building the MAGIS-100 atom interferometer to serve as a prototype gravitational wave detector in a frequency band between those addressed by LIGO and LISA, with potential for astrophysical discoveries, dark matter searches, and tests of quantum mechanics. Additionally, he is pursuing dark matter searches through collaborations involving cryogenic optical cavities. Kovachy has received several awards, including the Paul Ehrenfest Best Paper Award for Quantum Foundations in 2020, the David and Lucile Packard Fellowship for Science and Engineering in 2020, and the NIST Precision Measurement Grant in 2019.

Research topics

• Quantum mechanics
• Astrophysics
• Astronomy
• Physics

Selected publications

• Quantum effect observed for biggest objects yet

  Nature · 2026-01-21

  articleOpen access1st authorCorresponding
  PublisherOA PDFDOI

• Feynman diagrams for matter wave interferometry

  AVS Quantum Science · 2026-05-08

  preprintOpen accessSenior author

  We introduce a new theoretical framework based on Feynman diagrams to compute phase shifts in matter wave interferometry. The method allows for analytic computation of higher order quantum corrections, beyond the traditional semi-classical approximation. These additional terms depend on the finite size of the initial matter wavefunction and/or have higher order dependence on ℏ. We apply the method to compute the response of matter wave interferometers to power law potentials and potentials with an arbitrary spatial dependence. The analytic expressions are validated by comparing to numerical simulations, and estimates are provided for the scale of the quantum corrections to the phase shift response to the gravitational field of the earth, anharmonic trapping potentials, and gravitational fields from local proof masses. We also find that for certain experimentally feasible parameters, these corrections are large enough to be measured and could lead to systematic errors if they are not mitigated. We find that to first order in a spatially dependent potential, quantum corrections vanish when the initial matter wavepacket has spherical symmetry and the potential satisfies Laplace's equation. We anticipate these quantum corrections will be especially important for trapped matter wave interferometers and for free-space matter wave interferometers in the presence of proof masses. These interferometers are becoming increasingly sensitive tools for mobile inertial sensing, gravity surveying, tests of gravity and its interplay with quantum mechanics, and searches for dark energy.

  PublisherOA PDFDOI

• A surprising systematic effect from the interplay of spontaneous emission and many-pulse atom interferometry

  2026-03-05

  article1st authorCorresponding
  PublisherDOI

• Search for ultralight bosonic dark matter using two optical cavities

  2025-03-19

  articleSenior author
  PublisherDOI

• MAGIS-100 Experiment Installation in Shaft

  2025-06-05

  reportOpen access
  PublisherOA PDFDOI

• Characterizing atmospheric gravity gradient noise for vertical atom interferometers

  Physical review. D/Physical review. D. · 2025-04-09 · 6 citations

  articleOpen access

  Terrestrial long-baseline atom interferometer experiments are emerging as powerful tools for probing new fundamental physics, including searches for dark matter and gravitational waves. In the frequency range relevant to these signals, gravity gradient noise (GGN) poses a significant challenge. While previous studies for vertical instruments have focused on GGN induced by seismic waves, atmospheric fluctuations in pressure and temperature also lead to variations in local gravity. In this work, we advance the understanding of atmospheric GGN in vertical atom interferometers, formulating a robust characterization of its impact. We evaluate the effectiveness of underground placement of atom interferometers as a passive noise mitigation strategy. Additionally, we empirically derive global high- and low-noise models for atmospheric pressure GGN and estimate an analogous range for atmospheric temperature GGN. To highlight the variability of temperature-induced noise, we compare data from three prospective experimental sites. Our findings establish atmospheric GGN as comparable to seismic noise in its impact and underscore the importance of including these effects in site selection and active noise monitoring for future experiments.

  PublisherOA PDFDOI

• MAGIS-100 Experiment Facts

  2025-06-05

  reportOpen access
  PublisherOA PDFDOI

• Long-Baseline Atom Interferometry

  ArXiv.org · 2025-03-27

  preprintOpen access

  Long-baseline atom interferometry is a promising technique for probing various aspects of fundamental physics, astrophysics and cosmology, including searches for ultralight dark matter (ULDM) and for gravitational waves (GWs) in the frequency range around 1~Hz that is not covered by present and planned detectors using laser interferometry. The MAGIS detector is under construction at Fermilab, as is the MIGA detector in France. The PX46 access shaft to the LHC has been identified as a very suitable site for an atom interferometer of height $\sim 100$m, sites at the Boulby mine in the UK and the Canfranc Laboratory are also under investigation, and possible sites for km-class detectors have been suggested. The Terrestrial Very-Long-Baseline Atom Interferometry (TVLBAI) Proto-Collaboration proposes a coordinated programme of interferometers of increasing baselines.

  PublisherOA PDFDOI

• Clear skies ahead: characterizing atmospheric gravity gradient noise for vertical atom interferometers

  arXiv (Cornell University) · 2024-12-06

  preprintOpen access

  Terrestrial long-baseline atom interferometer experiments are emerging as powerful tools for probing new fundamental physics, including searches for dark matter and gravitational waves. In the frequency range relevant to these signals, gravity gradient noise (GGN) poses a significant challenge. While previous studies for vertical instruments have focused on GGN induced by seismic waves, atmospheric fluctuations in pressure and temperature also lead to variations in local gravity. In this work, we advance the understanding of atmospheric GGN in vertical atom interferometers, formulating a robust characterization of its impact. We evaluate the effectiveness of underground placement of atom interferometers as a passive noise mitigation strategy. Additionally, we empirically derive global high- and low-noise models for atmospheric pressure GGN and estimate an analogous range for atmospheric temperature GGN. To highlight the variability of temperature-induced noise, we compare data from three prospective experimental sites. Our findings establish atmospheric GGN as comparable to seismic noise in its impact and underscore the importance of including these effects in site selection and active noise monitoring for future experiments.

  PublisherOA PDFDOI

• Demonstration that Differential Length Changes of Optical Cavities are a Sensitive Probe for Ultralight Dark Matter

  arXiv (Cornell University) · 2024-12-30

  preprintOpen accessSenior author

  Measurements of differential length oscillations of Fabry-Perot cavities provide a sensitive and promising approach to searching for scalar ultralight dark matter (ULDM). The initial demonstration sets direct lower bounds that are one to two orders of magnitude lower for two model ULDM distributions -- a standard galactic halo and a relaxion star bound to Earth -- ranging over a decade of ULDM mass and Compton frequency. The demonstration suggests how a much higher sensitivity to a much larger ULDM mass range can be obtained.

  PublisherOA PDFDOI

Frequent coauthors

• Mark A. Kasevich

  Stanford University

  28 shared

• Jason M. Hogan

  Stanford University

  27 shared

• Alex Sugarbaker

  13 shared

• Philippe Bouyer

  13 shared

• Susannah Dickerson

  Harvard University

  12 shared

• Aurélien Hees

  12 shared

• Franck Pereira dos Santos

  Systèmes de Référence Temps-Espace

  12 shared

• C. Le Poncin-Lafitte

  Sorbonne Université

  12 shared

Labs

• Institute for Quantum Information Research and Engineering (INQUIRE)PI

  Fostering collaboration, innovation, and partnerships to position Northwestern as a leader in quantum information science and engineering (QISE).

Awards & honors

• Paul Ehrenfest Best Paper Award for Quantum Foundations (202…
• David and Lucile Packard Fellowship for Science and Engineer…
• National Institute of Standards and Technology Precision Mea…
• Fannie and John Hertz Foundation Fellowship (2009)