A novel artificial condensed matter lattice and a new platform for one-dimensional topological phases

DOI: 10.1126/sciadv.1501692

Authors: Ilya Belopolski (Princeton University) , Su-Yang Xu (Princeton University) , Nikesh Koirala (The State University of New Jersey) , Chang Liu (South University of Science and Technology of China) , Guang Bian (Princeton University) , Vladimir N. Strocov (Swiss Light Source) , Guoqing Chang (National University of Singapore) , Madhab Neupane (Princeton University) , Nasser Alidoust (Princeton University) , Daniel Sanchez (Princeton University) , Hao Zheng (Princeton University) , Matthew Brahlek (The State University of New Jersey) , Victor Rogalev (Swiss Light Source; University of Wuerzburg) , Timur Kim (Diamond Light Source) , Nicholas C. Plumb (Swiss Light Source) , Chaoyu Chen (Synchrotron SOLEIL) , François Bertran (Synchrotron SOLEIL) , Patrick Le Fèvre (Synchrotron SOLEIL) , Amina Taleb-Ibrahimi (Synchrotron SOLEIL) , Maria-Carmen Asensio (Synchrotron SOLEIL) , Ming Shi (Swiss Light Source) , Hsin Lin (National University of Singapore) , Moritz Hoesch (Diamond Light Source) , Seongshik Oh (The State University of New Jersey) , M. Zahid Hasan (Princeton University; Lawrence Berkeley National Laboratory)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Science Advances , VOL 3

State: Published (Approved)
Published: March 2017
Diamond Proposal Number(s): 11742

Abstract: Engineered lattices in condensed matter physics, such as cold-atom optical lattices or photonic crystals, can have properties that are fundamentally different from those of naturally occurring electronic crystals. We report a novel type of artificial quantum matter lattice. Our lattice is a multilayer heterostructure built from alternating thin films of topological and trivial insulators. Each interface within the heterostructure hosts a set of topologically protected interface states, and by making the layers sufficiently thin, we demonstrate for the first time a hybridization of interface states across layers. In this way, our heterostructure forms an emergent atomic chain, where the interfaces act as lattice sites and the interface states act as atomic orbitals, as seen from our measurements by angle-resolved photoemission spectroscopy. By changing the composition of the heterostructure, we can directly control hopping between lattice sites. We realize a topological and a trivial phase in our superlattice band structure. We argue that the superlattice may be characterized in a significant way by a one-dimensional topological invariant, closely related to the invariant of the Su-Schrieffer-Heeger model. Our topological insulator heterostructure demonstrates a novel experimental platform where we can engineer band structures by directly controlling how electrons hop between lattice sites.

Journal Keywords: phyics; materials science; topological insulator; Dirac fermion; Su-Schriffer-Heeger model

Subject Areas: Physics, Materials


Instruments: I05-ARPES

Added On: 29/03/2017 15:04

Documents:
e1501692.full.pdf

Discipline Tags:

Quantum Materials Physics Hard condensed matter - structures Materials Science

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES)