Pustelny Group — Quantum Sensing, Fundamental Physics, Spin Systems

PUSTELNY GROUP

Quantum Sensing, Fundamental Physics, Spin Systems

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OPTICAL ATOMIC MAGNETOMETRY

 

Optical atomic magnetometry uses laser light to prepare and probe atomic spins, turning their magnetic-field-dependent precession into an exceptionally sensitive measurement signal. Working with alkali-metal vapors, we develop magnetometers capable of femtotesla and, in optimized configurations, sub-femtotesla sensitivity. Our research spans magnetically shielded near-zero-field environments and measurements in Earth’s magnetic field, with applications in fundamental spin physics, zero-field NMR, and non-invasive biomagnetism.

OPTICALLY PUMPED MAGNETOMETERS & SPIN DYNAMICS

Atomic magnetometers also called optically pumped magnetometers (OPMs) use laser light to prepare polarized atomic spins in alkali-metal vapors and monitor their response to magnetic fields. Depending on the operating scheme, magnetic-field information can be extracted from spin precession or other magneto-optical signals, detected through changes in light polarization or transmission. Synchronous optical pumping can enhance the response by generating narrow magnetic resonances.

 

Our research focuses on coherent spin dynamics and magneto-optical resonances, including nonlinear magneto-optical rotation (NMOR) and synchronously pumped magnetometers. We investigate the effects of modulated light and time-dependent magnetic fields, and have developed rotating-polarization magnetometry to maintain high sensitivity over an extended magnetic-field range. We also study systematic effects that limit measurement sensitivity and accuracy.

Paraffin-coated alkali vapor cell

SPIN COHERENCE & ANTI-RELAXATION COATINGS

Preserving atomic spin coherence is essential for sensitive magnetometry. We use alkali-metal vapor cells with anti-relaxation wall coatings, including paraffin and alkene-based materials, which reduce spin depolarization during collisions with the cell walls. These coatings allow atomic polarization to survive many collisions, supporting long-lived spin coherence and narrow magnetic resonances.

SELF-COMPENSATING ATOMIC COMAGNETOMETERS

We investigate alkali–noble-gas comagnetometers, where optically polarized electron spins interact with noble-gas nuclear spins to form a coupled spin system. Near the self-compensation point, their response to slowly varying magnetic fields is strongly suppressed, while sensitivity to selected nonmagnetic spin interactions is retained.

Our work explores the coupled spin dynamics, stability, and frequency-dependent response of these sensors. Together with international collaborators, we developed and experimentally validated a general calibration method that uses measured magnetic-field responses to determine the sensitivity to different spin perturbations. This provides a foundation for reliable precision measurements and fundamental tests of physics.

Self-compensating alkali–noble-gas comagnetometer
Non-Hermitian spin dynamics in coupled atomic systems

NON-HERMITIAN SPIN DYNAMICS & PRECISION SENSING

Can the collective dynamics of interacting spins offer new possibilities for precision sensing? We explore this question by investigating non-Hermitian dynamics in coupled spin systems, where coherent interactions and dissipation jointly shape their response to weak perturbations.

Our research examines how the interplay between coupling, relaxation, and collective spin evolution influences sensor behavior and measurement performance. This emerging direction connects fundamental aspects of non-Hermitian physics with the opportunities and limitations of precision sensing.

BIOMAGNETISM & CUSTOM SCIENTIFIC ELECTRONICS

Biomagnetic Recordings: Because room-temperature vapor cells require no liquid-helium Dewars, the sensing volume can be positioned within millimeters of living tissue. We investigate optical magnetometry for non-invasive detection of human cardiac (magnetocardiography) and neural (magnetoencephalography) magnetic fields, as well as zero-field relaxometry of biological fluids.

Laser Stabilization & Timing Hardware: Operating femtotesla magnetometers across long measurement campaigns requires sub-MHz laser frequency stability and low-noise current control. Our laboratory designs wide-tuning dichroic atomic vapor laser locks (DAVLL), circuit-level magnetometer emulators, and GPS-disciplined multi-channel acquisition systems.

Magnetocardiography (MCG) recording with optical atomic magnetometers

SELECTED PUBLICATIONS IN OPTICAL MAGNETOMETRY

  • [Sensors 2025] S. Pustelny, P. Wlodarczyk, Rotating polarization magnetometry, Sensors 25, 2682 (2025) — DOI
  • [Physical Review Research 2024] M. Padniuk, E. Klinger, G. Łukasiewicz, D. Gavilan-Martin, T. Liu, S. Pustelny, D. F. Jackson Kimball, D. Budker, and A. Wickenbrock, Universal determination of comagnetometer response to spin couplings, Physical Review Research 6, 013339 (2024) — DOI
  • [Physical Review Applied 2023] E. Klinger, T. Liu, M. Padniuk, M. Engler, T. Kornack, S. Pustelny, D. F. Jackson Kimball, D. Budker, and A. Wickenbrock, Optimization of nuclear polarization in an alkali-noble gas comagnetometer, Physical Review Applied 19, 044092 (2023) — DOI
  • [Scientific Reports 2022] M. Padniuk, M. Kopciuch, R. Cipolletti, A. Wickenbrock, D. Budker, and S. Pustelny, Response of atomic-based sensors to magnetic and nonmagnetic perturbations, Scientific Reports 12, 324 (2022) — DOI
  • [Physical Review A 2020] R. S. Grewal and S. Pustelny, Transient dynamics of nonlinear magneto-optical rotation in the presence of a transverse magnetic field, Physical Review A 101, 033825 (2020) — DOI
  • [Scientific Reports 2019] P. Put, K. Popiołek, and S. Pustelny, Different sensitivities of two optical magnetometers realized in the same experimental arrangement, Scientific Reports 9, 2537 (2019) — DOI
  • [New Journal of Physics 2019] J. Sudyka, S. Pustelny, and W. Gawlik, Limitations of rotating-wave approximation in magnetic resonance: Characterization and elimination of the Bloch-Siegert shift in magneto-optics, New Journal of Physics 21, 023024 (2019) — DOI
  • [Review of Scientific Instruments 2019] P. Wlodarczyk, S. Pustelny, and D. Budker, System for control of polarization state of light and generation of light with continuously rotating linear polarization, Review of Scientific Instruments 90, 013110 (2019) — DOI
  • [Physical Review A 2019] P. Put, P. Wcisło, W. Gawlik, and S. Pustelny, Nonlinear magneto-optical rotation with parametric resonance, Physical Review A 100, 043838 (2019) — DOI
  • [Advances In Atomic, Molecular, and Optical Physics (Book Chapter, Academic Press) 2018] W. Cha┼éupczak, R. M. Godun, and S. Pustelny, Radio-frequency spectroscopy as a tool for studying coherent spin dynamics and for application to radio-frequency magnetometry, Advances In Atomic, Molecular, and Optical Physics (Book Chapter, Academic Press) 67, 297-336 (2018) — DOI