Exact numerical methods for a many-body Wannier-Stark system

• Verfasst von: Parra Murillo, Carlos Alberto [VerfasserIn]
• Verfasst von: Madroñero, Javier [VerfasserIn]
• Verfasst von: Wimberger, Sandro [VerfasserIn]
• Titel: Exact numerical methods for a many-body Wannier-Stark system
• Verf.angabe: Carlos A. Parra-Murillo, Javier Madroñero, Sandro Wimberger
• Jahr: 2015
• Jahr des Originals: 2014
• Umfang: 12 S.
• Fussnoten: Available online 11 October 2014 ; Gesehen am 30.06.2020
• Titel Quelle: Enthalten in: Computer physics communications
• Ort Quelle: Amsterdam : North Holland Publ. Co., 1969
• Jahr Quelle: 2015
• Band/Heft Quelle: 186(2015), Seite 19-30
• ISSN Quelle: 1879-2944
• DOI: doi:10.1016/j.cpc.2014.09.008
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: Bose-Hubbard model
• Sach-SW: Floquet problem
• Sach-SW: Lanczos algorithm
• Sach-SW: Optical lattices
• Sach-SW: Quantum chaos
• Sach-SW: Ultracold atoms
• Sach-SW: Wannier-Stark system
• K10plus-PPN: 170290864X

Abstract

We present exact methods for the numerical integration of the Wannier-Stark system in a many-body scenario including two Bloch bands. Our ab initio approaches allow for the treatment of a few-body problem with bosonic statistics and strong interparticle interaction. The numerical implementation is based on the Lanczos algorithm for the diagonalization of large, but sparse symmetric Floquet matrices. We analyze the scheme efficiency in terms of the computational time, which is shown to scale polynomially with the size of the system. The numerically computed eigensystem is applied to the analysis of the Floquet Hamiltonian describing our problem. We show that this allows, for instance, for the efficient detection and characterization of avoided crossings and their statistical analysis. We finally compare the efficiency of our Lanczos diagonalization for computing the temporal evolution of our many-body system with an explicit fourth order Runge-Kutta integration. Both implementations heavily exploit efficient matrix-vector multiplication schemes. Our results should permit an extrapolation of the applicability of exact methods to increasing sizes of generic many-body quantum problems with bosonic statistics.