[Landau ITP Seminars] Friday 21.04.2023

[Serge Krashakov]

Уважаемые коллеги!

На заседании Ученого совета в пятницу 21 апреля в 11:30  будет заслушан 
доклад:

Геннадий Ю. Шитов (Université de Sherbrooke)
*Brane order, quantum magnetism, and partition function zeros in 
modulated anisotropic ladders*

The presentation will be focused on the recent work [1] on the two-leg 
spin-1/2 ladders with anisotropy and two dimerization patterns 
(columnar/staggered). This model is equivalent to a modulated 
interacting fermionic Kitaev ladder. The Hartree-Fock approximation 
reduces the model to a sum of two quadratic effective Majorana 
Hamiltonians, which can be mapped onto two transverse quantum XY chains. 
This simplifies considerably calculations of the order parameters and 
analysis of the hidden symmetry breaking. The ground-state phase 
diagrams are found for each dimerization pattern. The diagrams contain 
phases with conventional antiferromagnetism, as well all those with 
non-local brane orders. We found analytically all the magnetizations and 
brane order parameters for the staggered case, as functions of couplings 
of the effective Hamiltonian, while the brane order parameters of the 
columnar ladder are found numerically from the Toeplitz determinants. 
The quantum phase transitions, disorder lines, ground-state 
factorization (disentanglement), and the additional attributes of 
topological order such as winding numbers and edge Majorana states, are 
shown to be determined by zeros of the partition function.
1. T. Pandey and G.Y. Chitov, Phys. Rev. B 106, 094413 (2022).


ID и пароль онлайн-трансляций в Zoom те же, что и для предыдущих 
трансляций докладов на Ученом совете:
https://zoom.us/j/96899364518?pwd=MzBsR2lYT0lYL2x2b1oyNU9LeWlWUT09
Meeting ID: 968 9936 4518
Пароль: 250319
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