ELFT HÍRADÓ

[Mihaly Gyorgy <mihaly AT szfki.hu>]

Prof. Yoshinori Tokura eloadasanak kezdete masfel oraval korabbra kerult,
azaz delelott 10 ora helyett 8.30-kor kezdodik (repulojarat valtozas miatt).

         2006. június 6. kedd, reggel. 8.30
BME Fizikai Intézet, Fizika Tanszék szemináriuma
Bp. XI. Budafoki út 8., F-épület, III. lépcsoház, II. em. 13.


                    Prof. Yoshinori Tokura
Department of Applied Physics, University of Tokyo
Correlated Electron Research Center, AIST Tsukuba

Competing orders and gigantic responses in transition-metal oxides with 
correlated electrons

Transition-metal oxides offer an intriguing playground to find interesting 
electronic property/functionality, such as high-temperature 
superconductivity in copper-oxides and colossal magnetoresistance in 
manganese-oxides.  In those materials, a vast number of electrons, 
comparable to the number of the constituent atoms, are strongly interacting 
with each other and tend to lose their mobility.  These correlated 
electrons with internal degrees of freedom- charge, spin, and orbital-, 
when placed on the specific topological atomic lattice, may form the rich 
and complex phases or the self-organized structures. Those are, for 
example, charge-spin stripes, charge-orbital ordered states, and 
liquid-crystal like states with anisotropic charge-spin-orbital 
correlations. Here I would present some of ample examples of the 
correlated-electron’s ordering patterns and show how dramatically they can 
respond to external stimuli, say, electric/magnetic fields, light, and 
pressure. In particular, the response of correlated electrons can be huge 
and fast in the vicinity of the boundary of the competing electronic 
phases, which promises future application. Topics I work on here include 
also the recent attempt to attain the gigantic magneto-electric effect in 
multiferroics; controlling the direction as well as the magnitude of 
electric polarization in terms of tiny magnetic field.




G. Mihaly
Department of Physics
Budapest University of Technology and Economics
http://dept.phy.bme.hu/