Seminar on Disorder and strong electron correlations: "Electron glass"
Starts 18 Jul 2012 17:00
Ends 18 Jul 2012 20:00
Central European Time
Leonardo da Vinci Building Luigi Stasi Seminar Room
Strada Costiera, 11
I - 34151 Trieste (Italy)
An electron glass (EG) is a disordered film with localized electronic states and hopping conduction. It has a long time relaxation (hours and days), that usually manifests itself in the slow change of the hopping conduction. Moreover, they may have a memory. Namely, conductivity of the film as a function of the electron density memorizes the density at which it has been cooled. Disordered films of InxO , films granulated by gold  or aluminum  are examples of EG’s. Important low energy excitations in such a system can be classified as single electron excitations that feature the so-called Coulomb Gap, and pair excitations that are random dipoles . I argue that the polarization of dipole interactions leads to a “polarization catastrophe” due to interaction of these excitations. As a result dipoles form a dipole glass . I propose that this is at the basis of glassy properties of the system. The width of the “memory dip” is calculated.
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