| Autor: |
Kostadinov IZ; Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA. kostadinov.1@osu.edu, Patton BR |
| Jazyk: |
angličtina |
| Zdroj: |
Physical review letters [Phys Rev Lett] 2008 Nov 28; Vol. 101 (22), pp. 226407. Date of Electronic Publication: 2008 Nov 26. |
| DOI: |
10.1103/PhysRevLett.101.226407 |
| Abstrakt: |
For first order metal-insulator transitions we show that, together with the dc conductance zero, there is a second critical point where the dielectric constant becomes zero and further turns negative. At this point the metallic reflectivity sharply increases. The two points can be separated by a phase separation state in a 3D disordered system but may tend to merge in 2D. For illustration we evaluate the dielectric function in a simple effective medium approximation and show that at the second point it turns negative. We reproduce the experimental data on a typical Mott insulator such as MnO, demonstrating the presence of the two points clearly. We discuss other experiments for studies of the phase separation state and a similar phase separation in superconductors with insulating inclusions. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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