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Calendar: ALS Calendar
Title: Susanne Stemmer, UCSB, April 22 290K Condensed Matter Seminar Speaker at UC Berkeley
When: 04/22/2013 2:30 PM - 3:30 PM
Description: Dr. Susanne Stemmer from UC Santa Barbara will be speaking on Mott/Band Insulator Heterostructures this coming Monday, April 22 at 3 Le Conte Hall, Berkeley. Her abstract is below.
Please sign up to meet individually with her on Monday or call (642-1967) or email me to sign you up. Her available times for meeting individually (in 575 Birge Hall) presently are:

9:00 AM - 9:30 AM (OPEN)
9:30 AM - 10:00 AM (OPEN)
4:15 PM - 4:45 PM (OPEN)
4:45 PM - 5:15 PM (OPEN)


Elaine Quiter, MS
Research Admin. Asst.
Hellman, Crommie, and Wang Groups and 290K Seminar
UC Berkeley - Physics
363 Birge Hall
Berkeley, CA 94720
Phone: 510-642-1967
Fax: 510-643-8497

Title: Mott/Band Insulator Heterostructures

Susanne Stemmer
Materials Department, University of California, Santa Barbara, California, 93106-5050, USA

Abstract: This talk will present recent work focused on using Mott/band insulator interfaces to probe correlation physics in transition metal oxides. The first example will introduce modulation doping as an approach for electrostatic control of large carrier densities in Mott materials and as a probe of the sensitivity of metal-insulator transitions to band filling. The approach is used to substantially change the charge carrier density in a NdNiO3 film, and we discuss the effects on the metal-insulator transition temperature. The second example concerns two-dimensional electron gases at interfaces between two insulating oxides that have attracted significant attention because they can exhibit unique properties, such as strong electron correlations, superconductivity and magnetism. We will discuss the interface between the strongly correlated Mott insulator GdTiO3, and the band insulator SrTiO3. A fixed polar interface charge is compensated by a high-density, two-dimensional electron gas (2DEG). This results in a high-density 2DEG, of approximately 1/2 electron per surface unit cell, or 3×1014 cm-2, for all GdTiO3/SrTiO3 heterostructures, independent of the individual layer thicknesses and growth sequences. We will present measurements of quantum oscillations that provide insights into the nature of a 2DEG derived from the Ti d-states. We will report on electron correlation effects, such as magnetism and mass enhancement, in extremely high carrier density SrTiO3 quantum wells that can be obtained using these interfaces. We also discuss the role of structure in the transition to an insulating state in very narrow quantum wells.

The work was done in collaboration with Pouya Moetakef, Clayton Jackson, Tyler Cain, Leon Balents, Jim Allen, Jack Zhang, Jinwoo Hwang, Junwoo Son, Jimmy Williams and David Goldhaber-Gordon.
Location: 3 Le Conte Hall, Berkeley
Author: Adriana Reza