Speaker
Description
We consider the spin-1/2 antiferromagnetic Heisenberg model on the frustrated octahedral chain in a presence of the external magnetic field. In a previous study [1], it was shown that the localized-magnon theory [2] can be modified for simpler calculation of concurrence [3], which may serve as a measure of the bipartite entanglement between nearest-neighbor and next-nearest-neighbor spins on squares of the octahedral chain. The results presented in [1] confirmed a new paradigm of the localized-magnons concept concerned with a simple calculation of entanglement measure. This study is devoted to further application of a modified localized-magnon theory for finding other entanglement measures. To be specific, we will consider such measures of entanglement as entanglement of formation and negativity [4-5]. It could be, thus, concluded that the localized-magnon theory can be straightforwardly adapted in order to calculate the respective entanglement measures for a wide class of flat-band quantum Heisenberg antiferromagnets.
[1] J. Strecka, O. Krupnitska and J. Richter, EPL, ${\bf 132}$ 30004 (2020).
[2] J. Schulenburg et al., Phys. Rev. Lett. ${\bf 88}$, 167207 (2002).
[3] L. Amico et al., Rev. Mod. Phys. ${\bf 80}$, 517 (2008).
[4] A. Peres, Phys. Rev. Lett. ${\bf 77}$, 1413 (1996).
[5] G. Vidal and R.F. Werner, Phys. Rev. A $\bf65$, 032314 (2002).
