Non-conventional orders, modulation, and disentanglement in low-dimensional quantum systems
Gennady Y. Chitov
Département de physique et Institut Quantique
Université de Sherbrooke
Présentation en anglais
Vidéoconférence, Zoom #: 821 4868 3936 (Zoom link)
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Abstract: The research to be discussed is focused on quantum phase transitions with non-conventional (topological) orders, such that the standard Landau paradigm does not work in a usual way. The main goal is to advance a new unifying theory to deal with different critical phenomena characterized by unconventional orders. The low-dimensional systems studied are mainly chains and ladders of quantum spins or fermions, with phases possessing distinct hidden orders. The latter are quantitatively described by the string or brane order parameters. The theory is advanced to calculate those quantities, along with duality transformations mapping them onto conventional local orders. Also, the winding numbers and zero-energy Majorana edge states, as additional attributes of topological order, are discussed. The modulation (i.e., appearance of oscillations in correlation functions) is related to the analytical properties of zeros of the partition functions. The latter are shown to contain all information needed for analysis of phase transitions, of modulation transitions (disorder lines), and of the ground-state factorization (disentanglement).
Cette conférence est présentée par le RQMP.
