Kulshreshtha, AK; Pal, A; Wahl, TB; Simon, SH; (2019) Approximating observables on eigenstates of large many-body localized systems. Physical Review B , 99 (10) , Article 104201. 10.1103/PhysRevB.99.104201.

Preview

Text PhysRevB.99.104201.pdf - Published Version Download (1MB) | Preview

Abstract

Eigenstates of fully many-body localized (FMBL) systems can be organized into spin algebras based on quasilocal operators called l bits. These spin algebras define quasilocal l -bit measurement ( τ z i ) and l -bit flip ( τ x i ) operators. For a disordered Heisenberg spin chain in the MBL regime we approximate l -bit flip operators by first calculating them exactly on small windows of systems using an algorithm called operator localization optimization. We then extend the l -bit operators onto the whole system by exploiting their quasilocal nature. We subsequently use these operators to represent approximate eigenstates of the Hamiltonian. Finally, we describe a method to calculate products of local observables on these eigenstates for systems of size L in O ( L 2 ) time. This method is used to calculate the variance of the energy of the approximate eigenstates, yielding an estimate of the error of the approximation.

Download activity - last month

Export as XMLCSVJSON

Download activity - last 12 months

Export as JSONCSVXML

Downloads by country - last 12 months

Export as XMLJSONCSV

Archive Staff Only

View Item