Correlation-Driven Charge Order in a Frustrated Two-Dimensional Atom Lattice

Autor: Ralph Claessen, Julian Maklar, Florian Adler, J. Schäfer, Stephan Rachel, Manuel Laubach, Andrzej Fleszar
Rok vydání: 2019
Předmět:
Zdroj: Physical Review Letters. 123
ISSN: 1079-7114
0031-9007
DOI: 10.1103/physrevlett.123.086401
Popis: We thoroughly examine the ground state of the triangular lattice of Pb on Si(111) using scanning tunneling microscopy. We detect charge-order, accompanied by a subtle structural reconstruction. Applying the extended variational cluster approach we map out the phase diagram as a function of local and non-local Coulomb interactions. Comparing the experimental data with the theoretical modeling leads us to conclude that electron correlations are the driving force of the charge-ordered state in Pb/Si(111), rather than Fermi surface nesting. These results resolve the discussion about the origin of the well known $3\times 3$ reconstruction forming below $86\,$K. By exploiting the tunability of correlation strength, hopping parameters and bandfilling, this material class represents a promising platform to search for exotic states of matter, in particular, for chiral topological superconductivity.
Comment: 6 pages, 4 figures. Update: included small refinements from the peer review process
Databáze: OpenAIRE