Research Highlights

Attosecond inner-shell lasing at ångström wavelengths

Observed and explained strong lasing phenomena during inner-shell lasing of copper and manganese leading to generation of attosecond X-ray pulses

Linker, T.M., Halavanau, A., Kroll, T. et al. Attosecond inner-shell lasing at ångström wavelengths. Nature 642, 934–940 (2025)

Scientists create the first attosecond atomic X-ray laser

Observation of polarization density waves in SrTiO₃

Detected polarization- density fluctuation resulting from strain and polarization in SrTiO3 by a novel picosec THz pump – X-ray probe experiment at LCLS​

Orenstein, G., Krapivin, V., Huang, Y. et al. Observation of polarization density waves in SrTiO3. Nat. Phys. 21, 961–965 (2025)

Tracking an Irreversible Light-Induced Creation of a Polar Supercrystal​

Single-shot X-ray diffraction over a time scales of seven orders of magnitude reveals how light creates a polar supercrystal with lattice periodicities of tens of nanometers.​

Stoica, V.A., Yang, T., Das, S. et al. Non-equilibrium pathways to emergent polar supertextures. Nat. Mater. 23, 1394–1401 (2024)

Orbital-selective time-domain signature of nematicity dynamics in the charge-density-wave phase of La_1.65Eu_0.2Sr_0.15CuO₄

Orbital-selective and time-resolved resonant x-ray scattering was used to study dynamics of both nematic order as well as charge density wave (CDW) order to learn of their origin, and how they melt.​

Direct observation of ultrafast cluster dynamics in supercritical carbon dioxide​

Experiments at the Linac Coherent Light Source discovered the ultrafast molecular dynamics within 10 ps in supercritical carbon dioxide. Collisions of unbounded molecules with clusters are responsible for momentum exchange​

Majumdar, A., Li, H., Muhunthan, P. et al. Direct observation of ultrafast cluster dynamics in supercritical carbon dioxide using X-ray Photon Correlation Spectroscopy. Nat Commun 15, 10540 (2024)

Giant terahertz birefringence in an ultrathin anisotropic semimetal​

We show that the polarization of light in the far infrared can be controlled using materials at the nanoscale, and demonstrate a new approach for characterizing the low frequency optical properties of materials using femtosecond electron diffraction.​

Sie et al., Nano Letters, 24, 20, 6031–6037 (2024). ​

Hidden phonon highways promote photoinduced interlayer energy transfer in twisted transition metal dichalcogenide heterostructures​

The heat transfer between stacked transition metal dichalcogenide (TMD) monolayers was revealed to be facilitated by a non-equilibrium phonon population.​

Pivotal Role of Disorder in Transition between Ordered Phases​

The first ultrafast PDF measurements show that an optically driven metal-insulator phase transition from between two distinct ordered states goes through disorder.​ The local disorder subsides in less than a pico second, however, the longer- range order continues to evolve for tens of picoseconds.​

Griffiths, J., Suzana, A.F., Wu, L. et al. Resolving length-scale-dependent transient disorder through an ultrafast phase transition. Nat. Mater. 23, 1041–1047 (2024)

Phonon-mediated attractive interactions in hybrid perovskite quantum dots

Showed that excitons in hybrid perovskite quantum dots lead to atomic-scale reorganizations which constructively interfere, leading to a new type of phonon-mediated attractive interaction. 

Yazdani, N., Bodnarchuk, M.I., Bertolotti, F. et al. Coupling to octahedral tilts in halide perovskite nanocrystals induces phonon-mediated attractive interactions between excitons. Nat. Phys. 20, 47–53 (2024)

Spin-driven shear oscillators in vdW antiferromagnets​

A strong coupling between spin order and interlayer shear in a van der Waals antiferromagnet FePS3 is manifested by giant shear oscillations induced by transient demagnetization.​

Zong, A., Zhang, Q., Zhou, F. et al. Spin-mediated shear oscillators in a van der Waals antiferromagnet. Nature 620, 988–993 (2023)

Artificial Intelligence for X-ray speckle studies​

A new artificial Intelligence (AI) algorithm has been designed to go beyond current capabilities for x-ray FEL studies on fluctuations in quantum materials.

H. Chen et al., "Testing the data framework for an AI algorithm in preparation for high data rate X-ray facilities," in 2022 4th Annual Workshop on Extreme-scale Experiment-in-the-Loop Computing (XLOOP), Dallas, TX, USA, 2022, pp. 1-9, doi: 10.1109/XLOOP56614.2022.00006.

Quantifying the exchange coupling between spins and topological bands in MnBi₂Te₄​

Quantified the exchange coupling between spins and topological bands in MnBi2Te4 using multimodal ultrafast optical spectroscopy.

Padmanabhan H, et al., Large Exchange Coupling Between Localized Spins and Topological Bands in MnBi₂ Te₄. Adv Mater. 2022 Dec;34(49):e2202841. doi: 10.1002/adma.202202841