Resonating-valence-bond physics is not always governed by the shortest tunneling loops
journal contributionposted on 2018-08-07, 10:43 authored by Arnaud Ralko, Ioannis RousochatzakisIoannis Rousochatzakis
It is well known that the low-energy sector of quantum spin liquids and other magnetically disordered systems is governed by short-ranged resonating-valence bonds. Here we show that the standard minimal truncation to the nearest-neighbor valence-bond basis fails completely even for systems where it should work the most, according to received wisdom. This paradigm shift is demonstrated for the quantum spin-1/2 square kagome, where strong geometric frustration, similar to the kagome, prevents magnetic ordering down to zero temperature. The shortest tunneling events bear the strongest longer-range singlet fluctuations, leading to amplitudes that do not drop exponentially with the length of the loop L, and to an unexpected loop-six valence-bond crystal, which is otherwise very high in energy at the minimal truncation level. The low-energy effective description gives in addition a clear example of correlated loop processes that depend not only on the type of the loop but also on its lattice embedding, a direct manifestation of the long-range nature of the virtual singlets.
This work is supported by the French National Research Agency through Grant No. ANR-2010-BLANC-0406-0 NQPTP.
Published inPhysical Review Letters
CitationRALKO, A. and ROUSOCHATZAKIS, I., 2015. Resonating-valence-bond physics is not always governed by the shortest tunneling loops. Physical Review Letters, 115 (16), 167202.
Publisher© American Physical Society
- AM (Accepted Manuscript)
Publisher statementThis work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/
NotesThis paper was published in the journal Physical Review Letters and the definitive published version is available at https://doi.org/10.1103/PhysRevLett.115.167202.