Intrinsic interfacial van der Waals monolayers and their effect on the high-temperature superconductor FeSe / SrTiO<sub>3</sub>
ORAL
Abstract
It was recently demonstrated that monolayer FeSe on a SrTiO3 substrate is a superconductor with Tc between 60 and 100 K, compared to 8 K in bulk FeSe. This is in contrast to the expected behavior; thinning a superconductor typically reduces Tc. Similar results have been obtained in monolayer FeSe deposited on BaTiO3 and on anatase or rutile TiO2. Here we determine the atomic structure of an interfacial layer and identify a possible role in driving the increase in Tc using a combination of quantum mechanical calculations and scanning transmission electron microscopy. Within our DFT calculations, this interfacial layer hosts long-range magnetic and orbital order not found in the typical TiO2 surface termination nor in previously identified surface reconstructions.
*[1] U.S. DOE grant DE-FG02-09ER46554 and the McMinn endowment at Vanderbilt University (HS, STP). [2] NERSC, a DOE Office of Science User Facility supported by the Office of Science of the U.S. DOE under Contract No. DE-AC02-05CH11231 (HS, STP). [3] U.S. DOE, Office of Science, BES, Materials Sciences and Engineering Division (DNL, AYB, TB, VRC, MFC). [4] U.S. NSF, DMR (DMR-1335215) (ZG, LL).
–
Presenters
-
Hunter Sims
- Francis Marion University, Vanderbilt University