BEGIN:VCALENDAR
VERSION:2.0
PRODID:researchseminars.org
CALSCALE:GREGORIAN
X-WR-CALNAME:researchseminars.org
BEGIN:VEVENT
SUMMARY:Piotr Sierant (ICFO)
DTSTART:20220519T070000Z
DTEND:20220519T080000Z
DTSTAMP:20260423T023941Z
UID:NMTP2022/13
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/NMTP2022/13/
 ">POLFED - a new diagonalization approach to study non-equilibrium phenome
 na</a>\nby Piotr Sierant (ICFO) as part of Numerical Methods in Theoretica
 l Physics\n\n\nAbstract\nI will describe polynomially filtered exact diago
 nalization (POLFED) method of computing eigenvectors of large sparse matri
 ces at arbitrary energies - a task that often arises when studying non-equ
 ilibrium phenomena in quantum many-body systems. The algorithm finds an op
 timal basis of a subspace spanned by eigenvectors with eigenvalues close t
 o a specified energy target by a spectral transformation using a high orde
 r polynomial of the matrix. The memory requirements scale much better with
  system size than in the state-of-the-art shift-invert approach\, while th
 e total CPU time used by the two methods is similar. Also\, the performanc
 e of POLFED is not severly impeded when the the number of non-zero element
 s in the matrix is increased allowing to efficiently study models with lon
 g-range interactions. A straightforward modification allows POLFED to inve
 stigate spectra of large Floquet unitary operators. I will demonstrate the
  potential of POLFED examining many-body localization transition in 1D int
 eracting quantum spin-1/2 chains.\n
LOCATION:https://researchseminars.org/talk/NMTP2022/13/
END:VEVENT
END:VCALENDAR