Diffusive transport in a quasiperiodic Fibonacci chain: absence of many-body localization at weak interactions

Varma, Vipin Kerala (avtor), Žnidarič, Marko (avtor)

We study high-temperature magnetization transport in a many-body spin-1/2 chain with on-site quasiperiodic potential governed by the Fibonacci rule. In the absence of interactions it is known that the system is critical with the transport described by a continuously varying dynamical exponent (from ballistic to localized) as a function of the on-site potential strength. Upon introducing weak interactions, we find that an anomalous noninteracting dynamical exponent becomes diffusive for any potential strength. This is borne out by a boundary-driven Lindblad dynamics as well as unitary dynamics, with agreeing diffusion constants. This must be contrasted to a random potential where transport is subdiffusive at such small interactions. Mean-field treatment of the dynamics for small U always slows down the noninteracting dynamics to subdiffusion, and is therefore unable to describe diffusion in an interacting quasiperiodic system. Finally, briefly exploring larger interactions we find a regime of interaction-induced subdiffusive dynamics, despite the on-site potential itself having no “rare regions.”

• Jezik: Angleški jezik
• Ključne besede: condensed matter physics
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FMF - Fakulteta za matematiko in fiziko
• Status publikacije: Objavljeno
• Različica publikacije: Recenzirani rokopis
• Leto izida: 2019
• Št. strani: Str. 085105-1-085105-14
• Številčenje: Vol. 100, iss. 8
• PID: 20.500.12556/RUL-113037
• UDK: 538.9
• ISSN pri članku: 2469-9950
• DOI: 10.1103/PhysRevB.100.085105
• COBISS.SI-ID: 3389284
• Datum objave v RUL: 29.11.2019

Gradivo je del revije

• Naslov: Physical review
• Založnik: American Physical Society
• ISSN: 2469-9950
• COBISS.SI-ID: 2997348

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: fizika kondenzirane snovi