Absence of localized edge modes in spite of a non-trivial Zak phase in BiCu2PO6

Abstract

Topological properties of physical systems have attracted tremendous interest in condensed matter and atomic physics in the last decade. Recently, magnetic solid state compounds with and without magnetic order have become a focus. We provide evidence that BiCu 2 PO 6 is a gapful, disordered quantum antiferromagnet with a non-trivial finite Zak phase, which characterizes one-dimensional systems. Our calculations show that in spite of the non-trivial topology no localized edge modes occur. This unexpected behavior is explained by a generic feature, namely the significance of direct and indirect gaps in topological systems.

Efficient flow equations for dissipative systems

“…Similar flow equations have been studied by the mathematicians Brockett, Chu und Driessel, called double bracket flow [22][23][24]. Flow equations have been applied on a wide range of problems including the Anderson model [25,26], the spin-boson model [27], electron-phonon interaction [28,29], quantum systems including an environment [30,31], spin chains with and without frustration [32][33][34][35], the quantum sine-Gordon models [36,37], Shastry-Sutherland lattices [38], spin ladders in copper nitrate [39] and coupled spin ladders in the compound BiCu 2 PO 6 [40]. Very often the goal is to decouple subspaces M n of different numbers n of quasi-particles by the change of basis.…”

Efficient flow equations for dissipative systems

“…Similar flow equations have been studied by the mathematicians Brockett, Chu und Driessel, called double bracket flow [22][23][24]. Flow equations have been applied on a wide range of problems including the Anderson model [25,26], the spin-boson model [27], electronphonon interaction [28,29], quantum systems including an environment [30,31], spin chains with and without frustration [32][33][34][35], the quantum sine-Gordon models [36,37], Shastry-Sutherland lattices [38], spin ladders in copper nitrate [39], coupled spin ladders in the compound BiCu 2 PO 6 [40], the Kondo model out of equilibrium [41], and a quenched Hubbard model [42]. Very often the goal is to decouple subspaces M n of different numbers n of quasiparticles by the change of basis.…”

Accessing Multi-triplons in Spin Ladders using Resonant Inelastic X-ray Scattering

“…We compute H eff and the corresponding effective observables up to order 10 in the directly evaluated enhanced perturbative CUT (deepCUT). The deepCUT approach allows for a non-perturbative evaluation of H eff and was proven to yield reliable results for the spin ladder up to x = 3 [42], while being stable even in the presence of frustration [43,44]. We choose a particle conserving generator m:n, which decouples only the first m quasiparticle sectors from all other sectors n [45,46].…”