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Bera, Soumya ; De Tomasi, Giuseppe ; Weiner, Felix ; Evers, Ferdinand

Density Propagator for Many-Body Localization: Finite-Size Effects, Transient Subdiffusion, and Exponential Decay

Artikel

Bera, Soumya, De Tomasi, Giuseppe, Weiner, Felix und Evers, Ferdinand (2017) Density Propagator for Many-Body Localization: Finite-Size Effects, Transient Subdiffusion, and Exponential Decay. Physical Review Letters 118 (19), S. 196801.

DOI zum Zitieren dieses Dokuments: 10.5283/epub.46115


Zusammenfassung

We investigate charge relaxation in quantum wires of spinless disordered fermions (t−V model). Our observable is the time-dependent density propagator Πϵ(x,t), calculated in windows of different energy density ϵ of the many-body Hamiltonian and at different disorder strengths W, not exceeding the critical value Wc. The width Δxϵ(t) of Πϵ(x,t) exhibits a behavior dlnΔxϵ(t)/dlnt=βϵ(t), where the ...

We investigate charge relaxation in quantum wires of spinless disordered fermions (t−V model). Our observable is the time-dependent density propagator Πϵ(x,t), calculated in windows of different energy density ϵ of the many-body Hamiltonian and at different disorder strengths W, not exceeding the critical value Wc. The width Δxϵ(t) of Πϵ(x,t) exhibits a behavior dlnΔxϵ(t)/dlnt=βϵ(t), where the exponent function βϵ(t)≲1/2 is seen to depend strongly on L at all investigated parameter combinations. (i) We confirm the existence of a region in phase space that exhibits subdiffusive dynamics in the sense that βϵ(t)<1/2 in a large window of times. However, subdiffusion might possibly be transient, only, finally giving way to a conventional diffusive behavior with βϵ=1/2. (ii) We cannot confirm the existence of many-body mobility edges even in regions of the phase diagram that have been reported to be deep in the delocalized phase. (iii) (Transient) subdiffusion 0<βϵ(t)≲1/2 coexists with an enhanced probability for returning to the origin Πϵ(0,t), decaying much slower than 1/Δxϵ(t). Correspondingly, the spatial decay of Πϵ(x,t) is far from Gaussian, being exponential or even slower. On a phenomenological level, our findings are broadly consistent with the effects of strong disorder and (fractal) Griffiths regions.



Beteiligte Einrichtungen


Details

DokumentenartArtikel
Titel eines Journals oder einer ZeitschriftPhysical Review Letters
VerlagAmerican Physical Society (APS)
Open Access ArtSHERPA/RoMEO
Band118
Nummer des Zeitschriftenheftes oder des Kapitels19
SeitenbereichS. 196801
Datum12 Mai 2017
Veröffentlichungsdatum25 Jun 2021 04:44
InstitutionenPhysik > Institut für Theoretische Physik > Lehrstuhl Ferdinand Evers
Identifikationsnummer
WertTyp
10.1103/PhysRevLett.118.196801DOI
Dewey-Dezimal-Klassifikation500 Naturwissenschaften und Mathematik > 530 Physik
StatusVeröffentlicht
BegutachtetJa, diese Version wurde begutachtet
An der Universität Regensburg entstandenZum Teil
URN der UB Regensburgurn:nbn:de:bvb:355-epub-461159
Dokumenten-ID46115

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