About

Michael James Lawson, M.D., M.B.B.S., F.R.A.C.P., is a volunteer clinical professor of medicine at UC Davis Health within the Department of Internal Medicine. His clinical expertise is in internal medicine and gastroenterology, with a focus on patient management and procedural techniques such as upper GI endoscopy, colonoscopy, liver biopsy, PEG placement, endoscopic retrograde cholangiopancreatography (ERCP), biliary stenting, capsule endoscopy, chromoendoscopy, and therapeutic interventional techniques for GI bleeding including variceal banding and single balloon enteroscopy. Dr. Lawson mentors gastroenterology fellows, guiding their career decisions in research, education, or private practice, and has recently mentored fellows in a GI endoscopy week in Rwanda. His research interests include a 15-year program for parents with children with IBS, involving education, behavioral modification, and dietary, sleep, and exercise interventions, which has resulted in numerous presentations, publications, and a book. His academic background includes a B.Sc. in Physiology from the University of New South Wales and an M.D. from the University of Adelaide. He has received several awards, including the Walter Trudeau Excellence in Teaching Award and the Morris F. Collen Lifetime Research Achievement Award.

Research topics

• Physics
• Particle physics
• Statistics
• Optics
• Quantum mechanics
• Nuclear physics

Selected publications

• Search for axionlike dark matter using liquid-state nuclear magnetic resonance

  Physical review. D/Physical review. D. · 2025-09-22 · 3 citations

  articleOpen access

  We search for dark matter in the form of axionlike particles (ALPs) in the mass range <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mn>5.576741</a:mn><a:mtext> </a:mtext><a:mtext> </a:mtext><a:mrow><a:mrow><a:mi>neV</a:mi></a:mrow><a:mo>/</a:mo><a:msup><a:mrow><a:mi mathvariant="normal">c</a:mi></a:mrow><a:mrow><a:mn>2</a:mn></a:mrow></a:msup></a:mrow><a:mo>−</a:mo><a:mn>5.577733</a:mn><a:mtext> </a:mtext><a:mtext> </a:mtext><a:mrow><a:mrow><a:mi>neV</a:mi></a:mrow><a:mo>/</a:mo><a:msup><a:mrow><a:mi mathvariant="normal">c</a:mi></a:mrow><a:mrow><a:mn>2</a:mn></a:mrow></a:msup></a:mrow></a:mrow></a:math> by probing their possible coupling to fermion spins through the ALP field gradient. This is achieved by performing proton nuclear magnetic resonance spectroscopy on a sample of methanol as a technical demonstration of the Cosmic Axion Spin Precession Experiment Gradient (CASPEr-Gradient) Low-Field apparatus. Searching for spin-coupled ALP dark matter in this mass range with associated Compton frequencies in a 240 Hz window centered at 1.348570 MHZ resulted in a sensitivity to the ALP-proton coupling constant of <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:msub><e:mi>g</e:mi><e:mi>ap</e:mi></e:msub><e:mo>≈</e:mo><e:mn>3</e:mn><e:mo>×</e:mo><e:msup><e:mn>10</e:mn><e:mrow><e:mo>−</e:mo><e:mn>2</e:mn></e:mrow></e:msup><e:mtext> </e:mtext><e:mtext> </e:mtext><e:msup><e:mrow><e:mi>GeV</e:mi></e:mrow><e:mrow><e:mo>−</e:mo><e:mn>1</e:mn></e:mrow></e:msup></e:math>. This narrow-bandwidth search serves as a proof-of-principle and a commissioning measurement, validating our methodology and demonstrating the experiment’s capabilities. CASPEr-Gradient Low-Field will probe the mass range from <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"><g:mrow><g:mn>4.1</g:mn><g:mtext> </g:mtext><g:mtext> </g:mtext><g:mi>peV</g:mi><g:mo>/</g:mo><g:msup><g:mrow><g:mi mathvariant="normal">c</g:mi></g:mrow><g:mrow><g:mn>2</g:mn></g:mrow></g:msup></g:mrow></g:math> to <j:math xmlns:j="http://www.w3.org/1998/Math/MathML" display="inline"><j:mrow><j:mn>17</j:mn><j:mtext> </j:mtext><j:mi>neV</j:mi><j:mo>/</j:mo><j:msup><j:mrow><j:mi mathvariant="normal">c</j:mi></j:mrow><j:mrow><j:mn>2</j:mn></j:mrow></j:msup></j:mrow></j:math> with hyperpolarized samples to boost the sensitivity beyond the astronomical limits.

  PublisherDOI

• Relative distance of entangled systems in emergent spacetime scenarios

  Physical review. D/Physical review. D. · 2023-03-10 · 1 citations

  articleOpen accessSenior author

  Spacetime emergence from entanglement proposes an alternative to quantizing gravity and typically derives a notion of distance based on the amount of mutual information shared across subsystems. Albeit promising, this program still faces challenges to describe simple physical systems, such as a maximally entangled Bell pair that is taken apart while preserving its entanglement. We propose a solution to this problem: a reminder that quantum systems can have multiple sectors of independent degrees of freedom, and that each sector can be entangled. Thus, while one sector can decohere, and decrease the amount of total mutual information within the system, another sector, e.g. spin, can remain entangled. We illustrate this with a toy model, showing that only within the particles' momentum uncertainty there can be considerably more entanglement than in the spin sector for a single Bell pair. We finish by introducing some considerations about how spacetime could be tested in the lab in the future.

  PublisherOA PDFDOI

• Atomic Layer Processing of MoS₂

  2023-03-01 · 1 citations

  article

  Molybdenum disulfide (MoS<inf>2</inf>) is one of several transition metal dichalcogenides consisting of a layer of transition atoms sandwiched between layers of chalcogens.[l] Interest in MoS<inf>2</inf> has been driven by the fact that it exhibits a 1.8 e V direct electronic band gap in monolayer form and retains a moderate electron mobility (>10 cm²/Vs) even when only ∽6.5 Å (three atoms) thick. [2] These properties offer potential for retaining or improving speed and efficiency in scaled electronic devices.

  PublisherDOI

• Searching for dark matter with plasma haloscopes

  Physical review. D/Physical review. D. · 2023 · 70 citations

  • Physics
  • Particle physics
  • Nuclear physics

  We summarize the recent progress of the Axion Longitudinal Plasma Haloscope (ALPHA) Consortium, a new experimental collaboration to build a plasma haloscope to search for axions and dark photons. The plasma haloscope is a novel method for the detection of the resonant conversion of light dark matter to photons. ALPHA will be sensitive to QCD axions over almost a decade of parameter space, potentially discovering dark matter and resolving the strong $CP$ problem. Unlike traditional cavity haloscopes, which are generally limited in volume by the Compton wavelength of the dark matter, plasma haloscopes use a wire metamaterial to create a tuneable artificial plasma frequency, decoupling the wavelength of light from the Compton wavelength and allowing for much stronger signals. We develop the theoretical foundations of plasma haloscopes and discuss recent experimental progress. Finally, we outline a baseline design for ALPHA and show that a full-scale experiment could discover QCD axions over almost a decade of parameter space.

  PublisherOA PDFDOI

• Transient radio lines from axion miniclusters and axion stars

  Physical review. D/Physical review. D. · 2023-03-13

  articleOpen access

  Gravitationally bound clumps of dark matter axions in the form of ``miniclusters'' or even denser ``axion stars'' can generate strong radio signals through axion-photon conversion when encountering highly magnetized neutron star magnetospheres. We systematically study encounters of axion clumps with neutron stars and characterize the axion infall, conversion and the subsequent propagation of the photons. We show that the high density and low escape velocity of the axion clumps lead to strong, narrow, and temporally characteristic transient radio lines with an expected duration varying from seconds to months. Our work comprises the first end-to-end modeling pipeline capable of characterizing the radio signal generated during these transient encounters, quantifying the typical brightness, anisotropy, spectral width, and temporal evolution of the radio flux. The methods developed here may prove essential in developing dedicated radio searches for transient radio lines arising from miniclusters and axion stars.

  PublisherOA PDFDOI

• Nucleation and growth of molybdenum disulfide grown by thermal atomic layer deposition on metal oxides

  Journal of Vacuum Science & Technology A Vacuum Surfaces and Films · 2022-11-21 · 4 citations

  articleOpen access

  To enable greater control over thermal atomic layer deposition (ALD) of molybdenum disulfide (MoS2), here we report studies of the reactions of molybdenum hexafluoride (MoF6) and hydrogen sulfide (H2S) with metal oxide substrates from nucleation to few-layer films. In situ quartz crystal microbalance experiments performed at 150, 200, and 250 °C revealed temperature-dependent nucleation behavior of the MoF6 precursor, which is attributed to variations in surface hydroxyl concentration with temperature. In situ Fourier transform infrared spectroscopy coupled with ex situ x-ray photoelectron spectroscopy (XPS) indicated the presence of molybdenum oxide and molybdenum oxyfluoride species during nucleation. Density functional theory calculations additionally support the formation of these species as well as predicted metal oxide to fluoride conversion. Residual gas analysis revealed reaction by-products, and the combined experimental and computational results provided insights into proposed nucleation surface reactions. With additional ALD cycles, Fourier transform infrared spectroscopy indicated steady film growth after ∼13 cycles at 200 °C. XPS revealed that higher deposition temperatures resulted in a higher fraction of MoS2 within the films. Deposition temperature was found to play an important role in film morphology with amorphous films obtained at 200 °C and below, while layered films with vertical platelets were observed at 250 °C. These results provide an improved understanding of MoS2 nucleation, which can guide surface preparation for the deposition of few-layer films and advance MoS2 toward integration into device manufacturing.

  PublisherOA PDFDOI

• Extraterrestrial Axion Search with the Breakthrough Listen Galactic Center Survey

  Physical Review Letters · 2022-12-13 · 62 citations

  articleOpen access

  Axion dark matter (DM) may efficiently convert to photons in the magnetospheres of neutron stars (NSs), producing nearly monochromatic radio emission. This process is resonantly triggered when the plasma frequency induced by the underlying charge distribution approximately matches the axion mass. We search for evidence of this process using archival Green Bank Telescope data collected in a survey of the Galactic Center in the C band by the Breakthrough Listen project. While Breakthrough Listen aims to find signatures of extraterrestrial life in the radio band, we show that their high-frequency resolution spectral data of the Galactic Center region is ideal for searching for axion-photon transitions generated by the population of NSs in the inner pc of the Galaxy. We use data-driven models to capture the distributions and properties of NSs in the inner Galaxy and compute the expected radio flux from each NS using state-of-the-art ray tracing simulations. We find no evidence for axion DM and set leading constraints on the axion-photon coupling, excluding values down to the level g_{aγγ}∼10^{-11} GeV^{-1} for DM axions for masses between 15 and 35 μeV.

  PublisherOA PDFDOI

• On the Relative Distance of Entangled Systems in Emergent Spacetime Scenarios

  arXiv (Cornell University) · 2022-10-26

  preprintOpen accessSenior author

  Spacetime emergence from entanglement proposes an alternative to quantizing gravity and typically derives a notion of distance based on the amount of mutual information shared across sub-systems. Albeit promising, this program still faces challenges to describe simple physical systems, such as a maximally entangled Bell pair that is taken apart while preserving its entanglement. We propose a solution to this problem: a reminder that quantum systems can have multiple sectors of independent degrees of freedom, and that each sector can be entangled. Thus, while one sector can decohere, and decrease the amount of total mutual information within the system, another sector, e.g. spin, can remain entangled. We illustrate this with a toy model, showing that only within the particles' momentum uncertainty there can be considerably more entanglement than in the spin sector for a single Bell pair. We finish by introducing some considerations about how spacetime could be tested in the lab in the future.

  PublisherOA PDFDOI

• Extraterrestrial Axion Search with the Breakthrough Listen Galactic Center Survey

  arXiv (Cornell University) · 2022-02-16 · 2 citations

  preprintOpen access

  Axion dark matter (DM) may efficiently convert to photons in the magnetospheres of neutron stars (NSs), producing nearly monochromatic radio emission. This process is resonantly triggered when the plasma frequency induced by the underlying charge distribution approximately matches the axion mass. We search for evidence of this process using archival Green Bank Telescope data collected in a survey of the Galactic Center in the C-Band by the Breakthrough Listen project. While Breakthrough Listen aims to find signatures of extraterrestrial life in the radio band, we show that their high-frequency resolution spectral data of the Galactic Center region is ideal for searching for axion-photon transitions generated by the population of NSs in the inner pc of the Galaxy. We use data-driven models to capture the distributions and properties of NSs in the inner Galaxy and compute the expected radio flux from each NS using state-of-the-art ray tracing simulations. We find no evidence for axion DM and set leading constraints on the axion-photon coupling, excluding values down to the level $g_{a γγ} \sim 10^{-11}$ GeV$^{-1}$ for DM axions for masses between 15 and 35 $μ$eV.

  PublisherOA PDFDOI

• Airborne Validation of ICESat-2 ATLAS Data Over Crevassed Surfaces and Other Complex Glacial Environments: Results From Experiments of Laser Altimeter and Kinematic GPS Data Collection From a Helicopter Over a Surging Arctic Glacier (Negribreen, Svalbard)

  Preprints.org · 2021-10-13 · 3 citations

  preprintOpen access

  The topic of this paper is the airborne evaluation of ICESat-2 Advanced Topographic Laser Altimeter System (ATLAS) measurement capabilities and surface-height-determination over crevassed glacial terrain, with a focus on the geodetical accuracy of geophysical data collected from a helicopter. To obtain surface heights over crevassed and otherwise complex ice surface, ICESat-2 data are analyzed using the density-dimension algorithm for ice surfaces (DDA-ice), which yields surface heights at the nominal 0.7~m along-track spacing of ATLAS data. As the result of an ongoing surge, Negribreen, Svalbard, provided an ideal situation for the validation objectives in 2018 and 2019, because many different crevasse types and morphologically complex ice surfaces existed in close proximity. Airborne geophysical data, including laser altimeter data (profilometer data at 905~nm frequency), differential Global Positioning System (GPS), Inertial Measurement Unit (IMU) data, on-board-time-lapse imagery and photographs, were collected during two campaigns in summers of 2018 and 2019. Airborne experiment setup, geodetical correction and data processing steps are described here. To date, there is relatively little knowledge of the geodetical accuracy that can be obtained from kinematic data collection from a helicopter. Our study finds that (1)~Kinematic GPS data collection with correction in post-processing yields higher accuracies than Real-Time-Kinematic (RTK) data collection. (2)~Processing of only the rover data using the Natural Resources Canada Spatial Reference System Precise Point Positioning (CSRS-PPP) software is sufficiently accurate for the sub-satellite validation purpose. (3)~Distances between ICESat-2 ground tracks and airborne ground tracks were generally better than 25~m, while distance between predicted and actual ICESat-2 ground track was on the order of 9~m, which allows direct comparison of ice-surface heights and spatial statistical characteristics of crevasses from the satellite and airborne measurements. (4)~The Lasertech Universal Laser System (ULS), operated at up to 300~m above ground level, yields full return frequency (400~Hz) and 0.06-0.08~m on-ice along-track spacing of height measurements. (5)~Cross-over differences of airborne laser altimeter data are 0.1918 $\pm$ 2.385~m along straight paths over generally crevassed terrain, which implies a precision of approximately 2.4~m for ICESat-2 validation experiments. (6)~In summary, the comparatively light-weight experiment setup of a suite of small survey equipment mounted on a Eurocopter (Helicopter AS-350) and kinematic GPS data analyzed in post-processing using CSRS-PPP leads to high accuracy repeats of the ICESat-2 tracks. The technical results (1)-(6) indicate that direct comparison of ice-surface heights and crevasse depths from the ICESat-2 and airborne laser altimeter data is warranted. The final result of the validation is that ICESat-2 ATLAS data, analyzed with the DDA-ice, facilitate surface-height determination over crevassed terrain, in good agreement with airborne data, including spatial characteristics, such as surface roughness, crevasse spacing and depth, which are key informants on the deformation and dynamics of a glacier during surge.

  PublisherOA PDFDOI

Frequent coauthors

• N. J. Curro

  University of California, Davis

  72 shared

• B. T. Bush

  University of California, Davis

  68 shared

• A. P. Dioguardi

  Los Alamos National Laboratory

  63 shared

• Lan Li

  Bohai University

  62 shared

• Samuel T. Weir

  Lawrence Livermore National Laboratory

  51 shared

• L. Steele

  50 shared

• Yogesh K. Vohra

  University of Alabama at Birmingham

  50 shared

• W.J. Evans

  The Ohio State University

  50 shared

Labs

• Gastroenterology and HepatologyPI

Education

• M.D., Medicine

  University of California, Davis

• Other, Medicine

  University of Sydney

Awards & honors

• Walter Trudeau Excellence in Teaching Award, 2018
• Honorary Professor La Universidad National, Autonoma de Nica…
• American College of Physicians Volunteerism Award, 2015
• Morris F. Collen Life Time Research Achievement Award from K…