Martin Greven
Associate Professor
309 Physics, email greven @ physics.umn.edu
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Previous Employment
Post-doctoral Research Associate, Massachusetts Institute of Technology, 1995-1997.
Assistant Professor of Applied Physics and Photon Science,
Stanford University, 1998-2009.
Awards and Honors
Alfred P. Sloan Fellow, 1999-01.
NSF CAREER Award, 2000-04.
Hellman Family Faculty Fund Award, 2003.
Fellow, American Physical Society, 2007.
Research Areas
Experimental condensed matter physics. Neutron and x-ray scattering of strongly correlated electron systems. High-temperature superconductivity. Low-dimensional magnetism. Crystal growth and characterization.Current Research
Our research focuses on the structure and dynamics of certain transition metal oxides in which strong electron correlations are important. These complex materials are at the frontier of research in condensed matter physics since they provide myriad possibilities to discover and study novel fundamental phenomena and phases, and because some of their properties have potential applications in technology.
The discovery by J. Georg Bednorz and K. Alexander Müller of high-temperature superconductivity in lamellar copper oxides has had a tremendous impact on this field, and it was awarded with the 1987 Physics Nobel Prize. The properties of these copper oxides are generally found to be highly anomalous and have eluded a huge amount of scientific effort to describe them within the context of conventional theories. Thus they present a formidable challenge to develop new theoretical concepts. In addition to the high-temperature superconductors, topics of current interest include low-dimensional model magnets and novel magnetic and charge ordering phenomena.
Materials preparation and processing are the heart of any successful materials physics endeavor. Our research involves the growth of high-quality single crystals using state-of-the-art image furnaces and encapsulation techniques.
The experimental techniques of X-ray and neutron scattering play invaluable roles in materials science and condensed matter physics, as they provide essential structural and magnetic information about new phases of matter and the transitions between them. This has been recognized throughout the world and resulted in the construction and upgrades of X-ray synchrotrons and neutron research facilities, such as the US Spallation Neutron Source. We pursue our scattering experiments at several domestic and international facilities.
Our research has been supported by the Department of Energy and the National Science Foundation.
Selected Publications
G. Yu, Y. Li, E. M. Motoyama, M. Greven , Universal relation between magnetic resonance and superconducting gap in unconventional superconductors, submitted to Nature Physics, arXiv:0903.2291v1 [abstract]
Y. Li, V. Balédent, N. Barišić, Y. Cho, B. Fauqué, Y. Sidis, G. Yu, X. Zhao, P. Bourges, M. Greven, Unusual magnetic order in the pseudogap region of the superconductor HgBa2CuO4+δ, Nature 455, 372 (2008). [abstract]
E. M. Motoyama, G. Yu, I. M. Vishik, O. P. Vajk, P. K. Mang, M. Greven, Spin correlations in the electron-doped high-transition-temperature superconductor Nd2-xCexCuO4+δ, Nature 455, 186 (2007) [abstract]
S. Larochelle, A. Mehta, L. Lu, P. K. Mang, O. P. Vajk, N. Kaneko, J. W. Lynn, L. Zhou, and M. Greven , Structural and Magnetic Properties of the Single-Layer Manganese Oxide La1-xSr1+xMnO4, Phys. Rev. B 71, 024435 (2005) [abstract]
O. P. Vajk, P. K. Mang, M. Greven, P. M. Gehring, J. W. Lynn, Quantum Impurities in the Two-dimensional Spin One-half Heisenberg Antiferromagnet, Science 295, 1691 (2002) [abstract]
Education
Ph.D. 1995, Massachusetts Institute of Technology.