Tailoring the nature and strength of electron–phonon interactions in the SrTiO3(001) 2D electron liquid

DOI: 10.1038/nmat4623

Authors: Z. Wang (Swiss Light Source, Paul Scherrer Institut) , S. Mckeown Walker (University of Geneva) , A. Tamai (University of Geneva) , Y. Wang (Stanford University) , Z. Ristic (École Polytechnique Fédérale de Lausanne (EPFL)) , F. Bruno (University of Geneva) , A. De La Torre (University of Geneva) , S. Ricco (University of Geneva) , N. C. Plumb (Swiss Light Source, Paul Scherrer Institut) , M. Shi (Swiss Light Source, Paul Scherrer Institut) , P. Hlawenka (Elektronenspeicherring BESSY-II) , J. Sánchez-Barriga (Elektronenspeicherring BESSY-II) , A. Varykhalov (Elektronenspeicherring BESSY-II) , Timur Kim (Diamond Light Source) , Moritz Hoesch (Diamond Light Source) , P. D. C. King (University of St Andrews) , Worawat Meevasana (Suranaree University of Technology, Thailand) , U. Diebold (Vienna University of Technology) , J. Mesot (Swiss Light Source, Paul Scherrer Institut) , B. Moritz (SLAC National Accelerator) , T. P. Devereaux (SLAC National Accelerator) , M. Radovic (Swiss Light Source, Paul Scherrer Institut) , F. Baumberger (University of Geneva)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nature Materials

State: Published (Approved)
Published: April 2016
Diamond Proposal Number(s): 11741

Abstract: Surfaces and interfaces offer new possibilities for tailoring the many-body interactions that dominate the electrical and thermal properties of transition metal oxides1, 2, 3, 4. Here, we use the prototypical two-dimensional electron liquid (2DEL) at the SrTiO3(001) surface5, 6, 7 to reveal a remarkably complex evolution of electron–phonon coupling with the tunable carrier density of this system. At low density, where superconductivity is found in the analogous 2DEL at the LaAlO3/SrTiO3 interface8, 9, 10, 11, 12, 13, our angle-resolved photoemission data show replica bands separated by 100 meV from the main bands. This is a hallmark of a coherent polaronic liquid and implies long-range coupling to a single longitudinal optical phonon branch. In the overdoped regime the preferential coupling to this branch decreases and the 2DEL undergoes a crossover to a more conventional metallic state with weaker short-range electron–phonon interaction. These results place constraints on the theoretical description of superconductivity and allow a unified understanding of the transport properties in SrTiO3-based 2DELs.

Journal Keywords: Electronic properties and materials; Materials science; Surfaces, Interfaces and thin films

Subject Areas: Physics, Materials


Instruments: I05-ARPES

Other Facilities: SIS at Swiss Light Source; 1^2 at BESSY II

Added On: 12/04/2016 10:24

Discipline Tags:

Surfaces Superconductors Quantum Materials Hard condensed matter - electronic properties Physics Materials Science interfaces and thin films

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES)