Projects per year
Abstract
We study the spreading of entanglement produced by the time evolution of a local fermionic excitation created above the ground state of the XXZ chain. The resulting entropy profiles are investigated via densitymatrix renormalization group calculations, and compared to a quasiparticle ansatz. In particular, we assume that the entanglement is dominantly carried by spinon excitations traveling at different velocities, and the entropy profile is reproduced by a probabilistic expression involving the density fraction of the spinons reaching the subsystem. The ansatz works well in the gapless phase for moderate values of the XXZ anisotropy, eventually deteriorating as other types of quasiparticle excitations gain spectral weight. Furthermore, if the initial state is excited by a local Majorana fermion, we observe a nontrivial rescaling of the entropy profiles. This effect is further investigated in a conformal field theory framework, carrying out calculations for the Luttinger liquid theory. Finally, we also consider excitations creating an antiferromagnetic domain wall in the gapped phase of the chain, and find again a modified quasiparticle ansatz with a multiplicative factor.
Original language  English 

Article number  005 
Journal  SciPost Physics 
Volume  10 
Issue number  1 
DOIs  
Publication status  Published  12 Jan 2021 
Keywords
 condmat.statmech
 hepth
Fingerprint
Dive into the research topics of 'Entanglement spreading after local fermionic excitations in the XXZ chain'. Together they form a unique fingerprint.Projects
 1 Finished

FWFVerschränkungen  Quantum fronts and entaglement driven by inhomogeneities
1/09/17 → 31/07/21
Project: Research project