Universität zu Köln

Koch-Janusz, Maciej, Khomskii, D. I. and Sela, Eran (2015). Affleck-Kennedy-Lieb-Tasaki State on a Honeycomb Lattice from t(2g) Orbitals. Phys. Rev. Lett., 114 (24). COLLEGE PK: AMER PHYSICAL SOC. ISSN 1079-7114

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Abstract

The two-dimensional Affeck-Kennedy-Lieb-Tasaki (AKLT) model on a honeycomb lattice has been shown to be a universal resource for quantum computation. In this valence bond solid, however, the spin interactions involve higher powers of the Heisenberg coupling ((S) over right arrow (i) . (S) over right arrow (j))(n), making these states seemingly unrealistic on bipartite lattices, where one expects a simple antiferromagnetic order. We show that those interactions can be generated by orbital physics in multiorbital Mott insulators. We focus on t(2g) electrons on the honeycomb lattice and propose a physical realization of the spin-3/2 AKLT state. We find a phase transition from the AKLT to the Neel state on increasing Hund's rule coupling, which is confirmed by density matrix renormalization group simulations. An experimental signature of the AKLT state consists of protected, free S = 1/2 spins on lattice vacancies, which may be detected in the spin susceptibility.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Koch-Janusz, Maciej UNSPECIFIED UNSPECIFIED UNSPECIFIED Khomskii, D. I. UNSPECIFIED UNSPECIFIED UNSPECIFIED Sela, Eran UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-401045
DOI:	10.1103/PhysRevLett.114.247204
Journal or Publication Title:	Phys. Rev. Lett.
Volume:	114
Number:	24
Date:	2015
Publisher:	AMER PHYSICAL SOC
Place of Publication:	COLLEGE PK
ISSN:	1079-7114
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language BOND GROUND-STATES; ANTIFERROMAGNETS Multiple languages Physics, Multidisciplinary Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/40104