ELFT HÍRADÓ

[Szeminárium koordinátor <sem-admin AT szfki.hu>]

SZFI SeminarRoósz GergőWigner RCP SZFIEntanglement of electrons and lattice 
in a Luttinger systemTuesday, 9 March 2021, 10:00, video conference, 
https://letsmeet.wigner.hu/szeminariumThe coupling between electronic and 
lattice degrees of freedom lies at the core of many important properties of 
solids. Nevertheless, surprisingly little is known about the entanglement 
between these degrees of freedom. Here, we calculate the entanglement entropy 
at zero temperature as well as the mutual information and the logarithmic 
entanglement negativity at finite temperatures between the electrons and the 
lattice for a one-dimensional chain. The electrons are described within 
Luttinger-liquid theory. Our results show that the entanglement entropy 
diverges when one approaches the limit of stability, the so-called 
Wentzel-Bardeen singularity. We find that the mutual information and the 
logarithmic entanglement negativity decrease with temperature. The mutual 
information reaches a finite value in the infinite-temperature limit, which 
is a consequence of the infinite linear electron spectrum of Luttinger 
theory. The logarithmic entanglement negativity becomes exactly zero above a 
certain temperature, i.e., the lattice and the electrons become non-entangled 
above this temperature. If the electron-electron interaction is unscreened or 
weakly screened, this characteristic temperature diverges with the system 
size. However, if the interaction is strongly screened the characteristic 
temperature is finite and independent of size, indicating a phase transition 
in the thermodynamic limit. Minden érdeklődőt szívesen látunk! - 
Everyone is welcome to attend.Róbert Juhászsem-admin AT szfki.hu