Topological Many-Body States in Quantum Antiferromagnets via Fuzzy Supergeometry

Recent vigorous investigations of topological order have not only discovered new topological states of matter, but also shed new light on “already known” topological states. One established example with topological order is the valence bond solid (VBS) states in quantum antiferromagnets. The VBS sta...

Full description

Bibliographic Details
Main Authors: Keisuke Totsuka, Kazuki Hasebe
Format: Article
Language:English
Published: MDPI AG 2013-04-01
Series:Symmetry
Subjects:
Online Access:http://www.mdpi.com/2073-8994/5/2/119
_version_ 1817990217596928000
author Keisuke Totsuka
Kazuki Hasebe
author_facet Keisuke Totsuka
Kazuki Hasebe
author_sort Keisuke Totsuka
collection DOAJ
description Recent vigorous investigations of topological order have not only discovered new topological states of matter, but also shed new light on “already known” topological states. One established example with topological order is the valence bond solid (VBS) states in quantum antiferromagnets. The VBS states are disordered spin liquids with no spontaneous symmetry breaking, but most typically manifest a topological order known as a hidden string order on the 1D chain. Interestingly, the VBS models are based on mathematics analogous to fuzzy geometry. We review applications of the mathematics of fuzzy supergeometry in the construction of supersymmetric versions of VBS (SVBS) states and give a pedagogical introduction of SVBS models and their properties. As concrete examples, we present detailed analysis of supersymmetric versions of SU(2) and SO(5) VBS states, i.e., UOSp(N|2) and UOSp(N|4) SVBS states, whose mathematics are closely related to fuzzy two- and four-superspheres. The SVBS states are physically interpreted as hole-doped VBS states with a superconducting property that interpolates various VBS states, depending on the value of a hole-doping parameter. The parent Hamiltonians for SVBS states are explicitly constructed, and their gapped excitations are derived within the single-mode approximation on 1D SVBS chains. Prominent features of the SVBS chains are discussed in detail, such as a generalized string order parameter and entanglement spectra. It is realized that the entanglement spectra are at least doubly degenerate, regardless of the parity of bulk (super)spins. The stability of the topological phase with supersymmetry is discussed, with emphasis on its relation to particular edge (super)spin states.
first_indexed 2024-04-14T00:56:25Z
format Article
id doaj.art-903c36e60815422c9fd5188ee9c7de3d
institution Directory Open Access Journal
issn 2073-8994
language English
last_indexed 2024-04-14T00:56:25Z
publishDate 2013-04-01
publisher MDPI AG
record_format Article
series Symmetry
spelling doaj.art-903c36e60815422c9fd5188ee9c7de3d2022-12-22T02:21:35ZengMDPI AGSymmetry2073-89942013-04-015211921410.3390/sym5020119Topological Many-Body States in Quantum Antiferromagnets via Fuzzy SupergeometryKeisuke TotsukaKazuki HasebeRecent vigorous investigations of topological order have not only discovered new topological states of matter, but also shed new light on “already known” topological states. One established example with topological order is the valence bond solid (VBS) states in quantum antiferromagnets. The VBS states are disordered spin liquids with no spontaneous symmetry breaking, but most typically manifest a topological order known as a hidden string order on the 1D chain. Interestingly, the VBS models are based on mathematics analogous to fuzzy geometry. We review applications of the mathematics of fuzzy supergeometry in the construction of supersymmetric versions of VBS (SVBS) states and give a pedagogical introduction of SVBS models and their properties. As concrete examples, we present detailed analysis of supersymmetric versions of SU(2) and SO(5) VBS states, i.e., UOSp(N|2) and UOSp(N|4) SVBS states, whose mathematics are closely related to fuzzy two- and four-superspheres. The SVBS states are physically interpreted as hole-doped VBS states with a superconducting property that interpolates various VBS states, depending on the value of a hole-doping parameter. The parent Hamiltonians for SVBS states are explicitly constructed, and their gapped excitations are derived within the single-mode approximation on 1D SVBS chains. Prominent features of the SVBS chains are discussed in detail, such as a generalized string order parameter and entanglement spectra. It is realized that the entanglement spectra are at least doubly degenerate, regardless of the parity of bulk (super)spins. The stability of the topological phase with supersymmetry is discussed, with emphasis on its relation to particular edge (super)spin states.http://www.mdpi.com/2073-8994/5/2/119quantum antiferromagnetsupersymmetryfuzzy spherematrix product statequantum entanglementtopological order
spellingShingle Keisuke Totsuka
Kazuki Hasebe
Topological Many-Body States in Quantum Antiferromagnets via Fuzzy Supergeometry
Symmetry
quantum antiferromagnet
supersymmetry
fuzzy sphere
matrix product state
quantum entanglement
topological order
title Topological Many-Body States in Quantum Antiferromagnets via Fuzzy Supergeometry
title_full Topological Many-Body States in Quantum Antiferromagnets via Fuzzy Supergeometry
title_fullStr Topological Many-Body States in Quantum Antiferromagnets via Fuzzy Supergeometry
title_full_unstemmed Topological Many-Body States in Quantum Antiferromagnets via Fuzzy Supergeometry
title_short Topological Many-Body States in Quantum Antiferromagnets via Fuzzy Supergeometry
title_sort topological many body states in quantum antiferromagnets via fuzzy supergeometry
topic quantum antiferromagnet
supersymmetry
fuzzy sphere
matrix product state
quantum entanglement
topological order
url http://www.mdpi.com/2073-8994/5/2/119
work_keys_str_mv AT keisuketotsuka topologicalmanybodystatesinquantumantiferromagnetsviafuzzysupergeometry
AT kazukihasebe topologicalmanybodystatesinquantumantiferromagnetsviafuzzysupergeometry