تقرير
Fock-space correlations and the origins of many-body localisation
| العنوان: | Fock-space correlations and the origins of many-body localisation |
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| المؤلفون: | Roy, Sthitadhi, Logan, David E. |
| المصدر: | Phys. Rev. B 101, 134202 (2020) |
| سنة النشر: | 2019 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Disordered Systems and Neural Networks, Condensed Matter - Statistical Mechanics, Condensed Matter - Strongly Correlated Electrons |
| الوصف: | We consider the problem of many-body localisation on Fock space, focussing on the essential features of the Hamiltonian which stabilise a localised phase. Any many-body Hamiltonian has a canonical representation as a disordered tight-binding model on the Fock-space graph. The underlying physics is however fundamentally different from that of conventional Anderson localisation on high-dimensional graphs because the Fock-space graph possesses non-trivial correlations. These correlations are shown to lie at the heart of whether or not a stable many-body localised phase can be sustained in the thermodynamic limit, and a theory is presented for the conditions the correlations must satisfy for a localised phase to be stable. Our analysis is rooted in a probabilistic, self-consistent mean-field theory for the local Fock-space propagator and its associated self-energy; in which the Fock-space correlations, together with the extensive nature of the connectivity of Fock-space nodes, are key ingredients. The origins of many-body localisation in typical local Hamiltonians where the correlations are strong, as well as its absence in uncorrelated random energy-like models, emerge as predictions from the same overarching theory. To test these, we consider three specific microscopic models, first establishing in each case the nature of the associated Fock-space correlations. Numerical exact diagonalisation is then used to corroborate the theoretical predictions for the occurrence or otherwise of a stable many-body localised phase; with mutual agreement found in each case. Comment: 25 pages, 10 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1103/PhysRevB.101.134202 |
| URL الوصول: | http://arxiv.org/abs/1911.12370 |
| رقم الأكسشن: | edsarx.1911.12370 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1103/PhysRevB.101.134202 |
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