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Diamond Light Source
Ravini, Tien-Lin, Arian, and Alex at the Diamond Light Source
Helmholtz-Zentrum Berlin
Lidia at BESSY II
Swiss Light Source
Weibing and Ravini at the Swiss Light Source
Diamond Light Source
Ravini, Tien-Lin, Arian, and Alex at the Diamond Light Source
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Review Articles and Book Chapters Overviewing Research Activities of the Group
Most Recent Research Highlight
Ultrafast THz Field Control of the Emergent Interfacial States
In this work, we show that intense single-cycle THz pulses effectively tune both the electronic structure and the interfacial ferromagnetism in epitaxial LaNiO₃/CaMnO₃ superlattices. Using advanced X-ray spectroscopies, we determine the magneto-optical profile and the thickness of the ferromagnetic interface. Time-resolved and temperature-dependent optical measurements then disentangle the correlated electronic and magnetic dynamics triggered by high-field THz excitation.
Recent Research Highlight
Depth-profiling emergent magnetic states at oxide interfaces
In this work, we used advanced X-ray spectroscopic and scattering techniques to study emergent interfacial ferromagnetism in CaMnO3/CaRuO3 oxide superlattices. We show that ferromagnetism extends beyond the interface into multiple CaMnO3 unit cells. Density functional calculations attribute this phenomenon to double exchange, driven by charge transfer from Ru to Mn. Oxygen vacancies influence interfacial magnetic moments, causing asymmetry between the top and bottom CaMnO3 layers. These results highlight the potential to engineer interfacial ferromagnetism via point defect manipulation.
Recent Research Highlight
Modulation-doping a Correlated Electron Insulator (VO2)
Abigail Derrico (co-author) now at UC Berkeley
In this work, we designed and synthesized modulation-doped VO2-based thin film heterostructures that closely emulate a textbook example of filling control in a correlated electron insulator. Using a combination of hard X-ray photoelectron spectroscopy (HAXPES), charge transport, and structural characterization, we showed that the insulating state can be doped to achieve carrier densities greater than 5e21 cm−3 without inducing any measurable structural changes. Remarkably, the insulating state is robust even at doping concentrations as high as ~0.2 e−/vanadium.
Research Highlight 1
Control of Phase Transitions in Strongly-Correlated Materials
One of the key scientific directions of our group is the study of phase transitions in strongly-correlated materials. We utilize external stimuli, such as THz pulses, temperature and strain to initiate and control the transition. Then we use static and ultrafast synchrotron– and FEL-based x-ray techniques to investigate and separate the various degrees of freedom involved in the process.
Research Highlight 2
Control of the Emergent Electronic Properties in Mott Oxides
Another important direction that our group pursues is the understanding and harnessing control of the emergent electronic phenomena in ultrathin Mott oxides. We utilize advanced polarization-dependent x-ray spectroscopic and scattering techniques in conjunction with state-of-the-art theory and synthesis to tune key electronic and structural parameters in ultrathin oxide films.
News and Events
November 24, 2025
Congratulations to Abby and Jay on a new paper on THz control of interfacial states published in Advanced Materials [link]
October 28, 2025
Check out a new preprint of our collaborative work with the May Group on ferromagnetic Kagome metals [link]
September 1, 2025
We are happy to welcome a new Ph.D. student, Esra Ayantuna, to the group
July 9, 2025
Congratulations to Sharup and Uditha on a new collaborative paper with the May Group in Phys. Rev. Materials [link]
June 27, 2025
Congratulations Alex on being promoted to Full Professor
February 9, 2025
Congratulations to Uditha and Sharup for completing a successful beamtime at the Diamond Light Source
November 21, 2024
Congratulations to Jay, Joseph, and Raj on a new paper in Nano Letters [link]
October 24, 2024
Check out a new preprint of our collaborative work on THz phonons in LaAlO3 with the Bonetti Group [link]
June 4, 2024
Alex to present the opening plenary talk at the HAXPES 2024 conference in Pilsen, Czech Republic
March 1, 2024
Congratulation to Lidia on winning the prestigious Diamond Scholars Fellowship
February 4, 2024
Check out a new preprint on our ultrafast THz study of emergent interfacial magnetism in oxide superlattices [link]
November 28, 2023
Congratulations to Lidia on winning the prestigious Creative Arts, Research, and Scholarship (CARAS) grant
November 17, 2023
Congratulations to Jay on successfully defending his Ph.D. thesis and accepting a postdoc offer from the Advanced Light Source (LBNL)
October 5, 2023
Congratulations to Abby and Jay on a new paper in Nature Communications [link]
August 29, 2023
Congratulations to Jay, Joseph, Abby, and Raj on a new paper in Phys. Rev. B [link]
August 23, 2023
Congratulations to Abby on starting her Ph.D. at UC Berkeley (Physics)
January 26, 2023
Congratulations to Jay and Raj on a new paper in Phys. Rev. Mat. [link]
November 11, 2022
Congratulations to Jay and Raj on a new paper in 2D Materials [link]
October 26, 2021
Congratulations to Bailey-Alexander on winning the Outstanding TA Award
October 9, 2021
Congratulations to Jay, Joseph, and Raj on a new paper in Phys. Rev. Mat. [link]
March 19, 2021
Congratulations to Alex on winning the Humboldt Fellowship for Experienced Researchers
February 16, 2021
Congratulations to Jay, Joseph, Raj, and Weibing on a new paper in Chemistry of Materials [link]
November 4, 2019
Congratulations to Arian on a new paper in Nano Letters [link]
September 9, 2019
Congratulations to Weibing on a new paper in Phys. Rev. B [link]
July 11, 2019
Congratulations to the entire group on successfully commissioning the high-flux HAXPES spectrometer [read story]
Research Highlight 3
Depth-Resolved Electronic Structure at Oxide Interfaces
Our group is involved in the development and advancement of novel depth-resolved x-ray spectroscopic techniques, such as the standing-wave photoemission and spectromicroscopy. We apply these techniques to studies of emergent electronic and magnetic phenomena at interfaces.
Recent Book Chapter (2018)
Research Highlight 4
Probing Bulk Electronic Structure with Hard X-ray Photoemission
Another important scientific direction of our group involves the development and applications of hard x-ray angle-resolved (as well as angle-integrated) photoemission techniques for bulk electronic structure determination.
Recent Book Chapter (2016)
Temple University
College of Science and Technology
Department of Physics
1925 N. 12th St. SERC 406
Philadelphia, PA 19122-1801
USA
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