Martin Greven
Director, CQM
Distinguished McKnight University Professor
Professor, School of Physics and Astronomy
Email: [email protected]
Phone: (612) 624-7542
Research interests:
Martin Greven’s research focus is on the structural, electronic and magnetic properties of select quantum materials, especially complex oxides. This materials class embodies many of the most profound contemporary questions pertaining to the collective quantum behavior of interacting electrons. His research involves bulk single crystal growth, neutron and X-ray scattering, as well as transport and magnetometry experiments. Projects led by Greven include rare-earth titanates, both in their Mott-insulating state and across the insulator-metal transition, unconventional superconductors (cuprates, bismuthates, strontium titanate), and incipient ferroelectrics (strontium titanate, potassium tantalate). Neutron and X-ray scattering are powerful probes that provide essential structural and magnetic information about new phases of matter and the transitions between them, and Greven pursues such experiments at leading facilities in the US (especially Oak Ridge National Lab and Argonne National Lab) and abroad. He and his collaborators are using novel high-force pneumatic strain cells to perform unprecedented in situ measurements, and they are pioneering the use of plastic deformation/dislocation engineering to enhance electronic properties and, in effect, create new quantum materials. Greven furthermore collaborates with experts in the use of complementary experimental techniques (e.g, Columbia University, EPFL, McMaster University, UC Berkeley/LBL, UC Davis, and Zagreb University).
Turan Birol
Associate Professor, Chemical Engineering and Materials Science
Email: [email protected]
Phone: (612) 301-1348
Research interests:
Turan Birol's research focuses on understanding the electronic and magnetic properties of crystalline materials and their connection with the crystal structure. In order to achieve this, he employs a combination of first-principles theoretical tools, including density functional theory and dynamic mean-field theory, as well as analytical approaches, such as group theory. Over the years, Birol has worked on materials such as ferroelectrics, multiferroics, topological materials, superconductors and various magnetic systems, with an emphasis on transition metal oxides. He has forged strong collaborative ties with experimentalists to help with the understanding of data generated by neutron and X-ray scattering as well as infrared, Raman and optical spectroscopy experiments.
Chris Leighton
Distinguished McKnight University Professor
Professor, Chemical Engineering and Materials Science
Email: [email protected]
Phone: (612) 625-4018
Research interests:
Chris Leighton's research generally focuses on electronic and magnetic properties of materials, spanning from bulk single crystals to thin films and heterostructures. In the context of the CQM, his work is focused on complex oxide materials, mostly delafossites, cobaltites, and titanates, including synthesis, structural/chemical characterization, and a wide range of physical property measurements. The latter include neutron scattering (including small-angle neutron scattering, neutron reflectometry, neutron powder diffraction, and inelastic neutron spectroscopy), as well as transport, magnetometry, heat capacity, and synchrotron X-ray scattering. His current projects in the CQM feature metallic delafossites (with Birol and Greven), doped Mott-insulating NiS2 and other complex sulfides (with Birol, Greven, and Xu), strain-tuned cobaltite films (with Birol and Greven), and various additional collaborative directions. Collaborations are ongoing with Oak Ridge National Lab, Argonne National Lab, the National Institute for Standards and Technology, and various other institutions, nationally and internationally. Recurring research themes include the understanding of competing forms of magnetic and electronic ordering in complex systems, and the interaction with defects and their control.
Xianghan Xu
Assistant Professor, School of Physics and Astronomy
Email: [email protected]
Phone: (612) 624-0480
Research interests:
Xianghan Xu’s research focuses on the design and growth of bulk single crystals of quantum materials with distinctive structural, magnetic, and electronic properties. The crystal growth techniques in his lab feature a 300-bar high-pressure laser floating zone (SCIDRE). In addition to growth facilities, the lab is equipped with an x-ray diffractometer and physical properties probes, including transport, magnetometry, dielectric, and heat-capacity measurements with a cryostat. Xu also employs neutron scattering to investigate symmetry-driven phenomena in magnetically ordered systems and spin excitations. His current projects within CQM focus on the growth and band engineering of strongly correlated systems near quantum criticality, as well as the design and realization of new magnetic lattices for quantum magnetism. Active collaborations are maintained with experts in fields such as microscopy, spectroscopy, and DFT calculations, as well as with institutions including Oak Ridge National Laboratory and a wide range of national and international collaborators.
Funded by the Department of Energy under DE-SC0016371
