Observation of a multitude of correlated states at the surface of bulk <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>1</mml:mn><mml:mi>T</mml:mi><mml:mtext>−</mml:mtext><mml:msub><mml:mi>TaSe</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math> crystals
Yi Chen, Wei Ruan, Jeffrey D. Cain, Ryan L. Lee, Salman Kahn, Caihong Jia, Alex Zettl, Michael F. Crommie
Abstract
Is it possible to have a single crystal that hosts a variety of correlated surface states? Layered transition metal dichalcogenides such as bulk 1$T$-TaSe${}_{2}$ offer a unique platform for accomplishing this since the electrons in each charge density wave (CDW) unit cell are susceptible to both Coulomb repulsion and interlayer coupling. By using scanning tunneling microscopy and spectroscopy, the authors identify here a multitude of correlated surface states that exist on bulk 1$T$-TaSe${}_{2}$ with properties ranging all the way from Mott insulating to strongly metallic Kondo behavior. 1$T$-TaSe${}_{2}$ thus simulates the full range of the periodic Anderson model within a single crystal by combining electron correlations with variable interlayer coupling.