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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Many-body localization: Transitions in spin models

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Schliemann, John [1] ; Costa, I, Joao Vitor ; Wenk, Paul [1] ; Egues, J. Carlos [2]
Total Authors: 4
[1] Univ Regensburg, Inst Theoret Phys, Regensburg - Germany
[2] Costa, Joao Vitor, I, Univ Sao Paulo, Inst Fis Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Physical Review B; v. 103, n. 17 MAY 13 2021.
Web of Science Citations: 0

We study the transitions between ergodic and many-body localized phases in spin systems, subject to quenched disorder, including the Heisenberg chain and the central spin model. In both cases systems with common spin lengths 1/2 and 1 are investigated via exact numerical diagonalization and random matrix techniques. Particular attention is paid to the sample-to-sample variance (Delta(s)r)(2) of the averaged consecutive-gap ratio < r > for different disorder realizations. For both types of systems and spin lengths we find a maximum in Delta(s)r as a function of disorder strength, accompanied by an inflection point of < r >, signaling the transition from ergodicity to many-body localization. The critical disorder strength is found to be somewhat smaller than the values reported in the recent literature. Further information about the transitions can be gained from the probability distribution of expectation values within a given disorder realization. (AU)

FAPESP's process: 16/08468-0 - Topological insulators and Majorana fermions
Grantee:José Carlos Egues de Menezes
Support type: Regular Research Grants
FAPESP's process: 18/19017-4 - Many-body localization: central spin models
Grantee:José Carlos Egues de Menezes
Support type: Research Grants - Visiting Researcher Grant - International
FAPESP's process: 20/00841-9 - Shubnikov-de-Haas Oscillations in topological and non-topological electron systems
Grantee:José Carlos Egues de Menezes
Support type: Regular Research Grants