Charge Instability in Single-Layer TiTe_{2} Mediated by van der Waals Bonding to Substrates

Meng-Kai Lin; Joseph A Hlevyack; Peng Chen; Ro-Ya Liu; Sung-Kwan Mo; T-C Chiang

doi:10.1103/PhysRevLett.125.176405

Charge Instability in Single-Layer TiTe_{2} Mediated by van der Waals Bonding to Substrates

Phys Rev Lett. 2020 Oct 23;125(17):176405. doi: 10.1103/PhysRevLett.125.176405.

Authors

Meng-Kai Lin^{1

2}, Joseph A Hlevyack^{1

2}, Peng Chen³, Ro-Ya Liu^{1

2

4

5}, Sung-Kwan Mo⁴, T-C Chiang^{1

2}

Affiliations

¹ Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
² Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
³ Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science and Shanghai Center for Complex Physics, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China.
⁴ Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
⁵ Institute of Physics, Academia Sinica, Taipei 10617, Taiwan.

PMID: 33156647
DOI: 10.1103/PhysRevLett.125.176405

Abstract

Single layers of transition metal dichalcogenides are of interest for emergent properties; an often-neglected issue is substrate effects. Our experiments show that the charge density wave in a single-layer TiTe_{2} grown on PtTe_{2} films is strongly suppressed by increasing the PtTe_{2} substrate thickness. Given that the interfacial bonding remains of the weak incommensurate van der Waals type, the observed changes are correlated with a thickness-dependent metallicity transformation in the PtTe_{2} substrate. The results illustrate the crucial role of the substrate in single-layer physics.