Complex oxides

Polaron-Plasmon Superconductivity in Strontium Titanate

Speaker(s): 
Alex Edelman
Dates: 
Wednesday, June 7, 2017 - 4:00pm to 5:00pm

Strontium titanate is a bulk insulator that becomes superconducting at remarkably low carrier densities. Even more enigmatic properties become apparent at the strontium titanate/lanthanum aluminate (STO/LAO) interface and it is important to disentangle the effects of reduced dimensionality from the poorly-understood pairing mechanism. Recent experiments measuring the surface photoemission spectrum[1] and bulk tunneling spectrum[1] have found a cross-over, as a function of carrier density, from a polaronic regime with substantial spectral weight associated with strongly...

Giant Conductivity Switching of LaAlO3/SrTiO3 Heterointerfaces Governed by Surface Protonation

  • By Aude Marjolin
  • 22 February 2016

In their latest article, Jeremy Levy and his group put forward compelling experimental evidence of the role of surface chemistry on conductivity in complex oxides heterostructures. 

This work, published in Nature Communications on February 10, 2016 illustrates how the conductivity of the 2DEG layer in LAO/STO can be modulated using solvent immersion and illumination. 

Swing-Dancing Electron Pairs

  • By Aude Marjolin
  • 13 May 2015

A research team led by PQI faculty Jeremy Levy has discovered electrons that can "swing dance". This unique electronic behavior can potentially lead to new families of quantum devices.

Superconductors, materials that permit electrical current to flow without energy loss, form the basis for magnetic resonance imaging devices as well as emergingtechnologies such as quantum computers. At the heart of all superconductors is the bunching of electrons into pairs.

The work, done in collaboration with researchers from the University of Wisconsin-Madison and the U.S. Naval Research Laboratory, was published May 14 in the journal Nature.