Group News
Group Moving
Our group is going to join the Department of Physics and Astronomy at Louisiana State University starting at the begining of 2009. See details in Material Science Program
Scholarships
Congratulations to both Diane Alvarez and Yi Li! Diane is a receipient of the graduate scholarship from Alfred P. Sloan Foundation. Yi is awarded with the Ecenomic Development Assistantship for pursuing her Ph. D. degree by Stephenson Enterpreneurship Institute at LSU.
News from En Cai
Congratulations to En Cai! She got her master degree in physics from FIU and is pursuing her PH.D in UIUC. Anne, good luck!
A new PRL paper published
Our another new PRL paper titled "Manifestations of Broken Symmetry: The Surface Phases of Ca2-xSrxRuO4" is just appeared here.
The new XPS/UPS setup grouped in our system
Our high-resolution XPS/UPS system has nicely integrated into our UHV
Laser-MBE/STM system, which is able to determine the chemical
composition, bonding information and electronic propertiesof in-situ grown
correlated elelectron materials.
A New SCIENCE Paper about Inherent Mott Metal-to-Insulator Transition
Broadly speaking, a material can be classified as a metal if it contains itinerant electric charges ready for carrying electric current. The opposite is true in the case of insulators. In these, electric charges are localized and cannot move, so no electric conductivity exists. In a new class of so called correlated electron materials, such as high-temperature superconductors, electrons strongly interact and give rise to extraordinary phenomena including superconductivity. One such phenomenon is the Mott metal-insulator transition, originally discovered by Sir Nevill Mott, who won the 1977 Nobel Prize in Physics for his study of phase transitions from a metal to an insulator in certain materials, and for showing that these transitions are inherently driven by electron-electron interactions. Experimentally, Mott transitions can be produced but nearly always are accompanied by a structure transition, until now. In the October 26 issue of SCIENCE (volume 318, page 615), Prof. Jiandi Zhang of the Department of Physics, in collaboration with Prof. Plummer’s group at the University of Tennessee-Knoxville (UTK), R. Jin and D. Mandrus at Oak Ridge National Laboratory (ORNL), as well as his colleagues at the Institute of Physics in Beijing, China, demonstrates that a purely electronic Mott metal-to-insulator transition occurs at a crystalline surface of a transition-metal oxide. The broken translational symmetry at the surface creates this phase transition without participation of a crystal structural transformation. This finding offers a unique opportunity to gain insight into the nature of an inherent Mott transition, which is a key topic of study in condensed matter physics today.
New funding for photoelectron spectroscopy setup
It is great news that our proposal on “Acquisition of an X-ray/UV photoelectron spectroscopy setup for materials research and education” has been funded by US department of Defense/Infrastructure Support Program. This new setup, which can provide us information of chemical composition and electronic properties, will be integrated with our current laser-MBE/STM for the studies of the surfaces and interfaces of oxide materials.
A review article for the spin-waves in ferromegnetic metallic manganites
Doped manganese oxides (manganites) are of interest not only because they are a testing ground of the classicaldouble-exchange (DE) interaction mechanism for the observed “colossal” magnetoresistance (CMR), but alsobecause they exhibit an extraordinaryarena of emergent phenomena. Through the collaboration with colleagues at the University of Tennessee, ORNL, etc., we have systematically studied the unusual spin-waves behavior in ferromagnetic metallic manganites. The results are summarized in a recent invited review article to be appeared in J. of Physics: Conden. Matter.
Figure: Inelastic neutron scattering measured FM Magnon excitation energy of a prototype CMR single crystal (La0.7Ca0.7MnO3) plotted as a function of momentum qx and qy in the momentum space (lower sheet) with a large Brillouin zone boundary (qx, qy = ± 0.5) deviation (indicated by the arrow) from the expected values (upper sheet) from the simple DE Model.
News from En Cai
En Cai got the first place in the Graduate Student Research Competition of Department of Physics, FIU.
News from Dr. Hongwei Qu
Our former group member, Dr. Hongwei Qu has become an assistant professor in the Department of Electric and Computer Engineering, Oakland University. Congratulations to Hongwei and best wishes to him!
Hao Sha has won two prizes
2006 Scholarly Forum, Research Paper and Oral Presentations Competition for Graduate Students Presented by Graduate Students Association (GSA) of FIU
Second Prize in Chemistry and Physics Category
Material Advantage Oral Technical Presentation
Presented by Material Advantage Chapter at FIU
First Prize
News from our former group member
Our former group member, Hongwei Qu, with his current group members at the University of Florida, recently successfully designed a tiny, easy-to-manufacture motion sensor, a development that could help popularize the sensors as standard equipment in personal electronics, medical devices and other applications. For details,please go to http://www.sciencedaily.com/releases/2006/02/060210090229.htm
New PRL papers come out
Two recent papers from our group collaborating with colleagues at Oak Ridge National Lab, etc. have been published in Physics Review Letters (PRL). Evolution of Spin-Wave Excitations in Ferromagnetic Metallic Manganites, Phys. Rev. Lett. 96, 047204 (2006).Dopant-Induced Nanoscale Electronic Inhomogeneity in Ca2-xSrxRuO4, Phys. Rev. Lett. 96, 066401 (2006).
March Meeting
Both Lei Cai and Hao Sha are going to give an oral presentation in the coming March Meeting of American Physical Society at Baltimore, Maryland. Lei Cai will talk about his theoretical work on a nanoscale dipole flipping at the surface of a ferroelectric copolymer film. Hao Sha will talk about his recent study of magnetic inhomogeneities in manganites by using neutron scattering. (Jan 20, 2006)
Congratulations to DR. Chenxi Lu!!!
After five years hard working, Chenxi Lu get his Ph.D on August 2005 with dissertation “The Correlation of Structure and Electronic Properties near the Surface of Transition Metal Oxides”. (Sep 1, 2005)
NSF Career Award
Dr. Zhang has just received a CAREER Award from the National Science Foundation. This award will provide fund for the study of New Phases at the Surface/Interfaces of Transition Metal Oxides. (Feb 1, 2004)
DOE Research Award
Our Materials Physics group has received another grant from the Department of Energy for the Research and Training of Using Neutron Scattering to Probe the Collective Phenomena in Doped Transition-Metal Oxides. More graduate students will be involved in the studies of complex materials with neutron! (Feb 1, 2004)