Particle-hole symmetry, many-body localization, and topological edge modes
We study the excited states of interacting fermions in one dimension with particle-hole symmetric disorder (equivalently, random-bond XXZ chains) using a combination of renormalization group methods and exact diagonalization. Absent interactions, the entire many-body spectrum exhibits infinite-rando...
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| Format: | Journal article |
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American Physical Society
2016
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| _version_ | 1826285454926807040 |
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| author | Vasseur, R Friedman, A Parameswaran, S Potter, A |
| author_facet | Vasseur, R Friedman, A Parameswaran, S Potter, A |
| author_sort | Vasseur, R |
| collection | OXFORD |
| description | We study the excited states of interacting fermions in one dimension with particle-hole symmetric disorder (equivalently, random-bond XXZ chains) using a combination of renormalization group methods and exact diagonalization. Absent interactions, the entire many-body spectrum exhibits infinite-randomness quantum critical behavior with highly degenerate excited states. We show that though interactions are an irrelevant perturbation in the ground state, they drastically affect the structure of excited states: Even arbitrarily weak interactions split the degeneracies in favor of thermalization (weak disorder) or spontaneously broken particle-hole symmetry, driving the system into a many-body localized spin glass phase (strong disorder). In both cases, the quantum critical properties of the noninteracting model are destroyed, either by thermal decoherence or spontaneous symmetry breaking. This system then has the interesting and counterintuitive property that edges of the many-body spectrum are less localized than the center of the spectrum. We argue that our results rule out the existence of certain excited state symmetry-protected topological orders. |
| first_indexed | 2024-03-07T01:29:05Z |
| format | Journal article |
| id | oxford-uuid:92fd73fc-e844-4035-bf69-96cdf38abb3b |
| institution | University of Oxford |
| last_indexed | 2024-03-07T01:29:05Z |
| publishDate | 2016 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | oxford-uuid:92fd73fc-e844-4035-bf69-96cdf38abb3b2022-03-26T23:29:17ZParticle-hole symmetry, many-body localization, and topological edge modesJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:92fd73fc-e844-4035-bf69-96cdf38abb3bSymplectic Elements at OxfordAmerican Physical Society2016Vasseur, RFriedman, AParameswaran, SPotter, AWe study the excited states of interacting fermions in one dimension with particle-hole symmetric disorder (equivalently, random-bond XXZ chains) using a combination of renormalization group methods and exact diagonalization. Absent interactions, the entire many-body spectrum exhibits infinite-randomness quantum critical behavior with highly degenerate excited states. We show that though interactions are an irrelevant perturbation in the ground state, they drastically affect the structure of excited states: Even arbitrarily weak interactions split the degeneracies in favor of thermalization (weak disorder) or spontaneously broken particle-hole symmetry, driving the system into a many-body localized spin glass phase (strong disorder). In both cases, the quantum critical properties of the noninteracting model are destroyed, either by thermal decoherence or spontaneous symmetry breaking. This system then has the interesting and counterintuitive property that edges of the many-body spectrum are less localized than the center of the spectrum. We argue that our results rule out the existence of certain excited state symmetry-protected topological orders. |
| spellingShingle | Vasseur, R Friedman, A Parameswaran, S Potter, A Particle-hole symmetry, many-body localization, and topological edge modes |
| title | Particle-hole symmetry, many-body localization, and topological edge modes |
| title_full | Particle-hole symmetry, many-body localization, and topological edge modes |
| title_fullStr | Particle-hole symmetry, many-body localization, and topological edge modes |
| title_full_unstemmed | Particle-hole symmetry, many-body localization, and topological edge modes |
| title_short | Particle-hole symmetry, many-body localization, and topological edge modes |
| title_sort | particle hole symmetry many body localization and topological edge modes |
| work_keys_str_mv | AT vasseurr particleholesymmetrymanybodylocalizationandtopologicaledgemodes AT friedmana particleholesymmetrymanybodylocalizationandtopologicaledgemodes AT parameswarans particleholesymmetrymanybodylocalizationandtopologicaledgemodes AT pottera particleholesymmetrymanybodylocalizationandtopologicaledgemodes |