The Uhlmann connection in fermionic systems undergoing phase transitions
| Autor: | Nikola Paunković, Vítor R. Vieira, Chrysoula Vlachou, Bruno Mera |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Superconductivity
Physics Phase transition Quantum Physics Strongly Correlated Electrons (cond-mat.str-el) FOS: Physical sciences General Physics and Astronomy Parameter space BCS theory 01 natural sciences 010305 fluids & plasmas Connection (mathematics) Theoretical physics MAJORANA Condensed Matter - Strongly Correlated Electrons Topological insulator Condensed Matter::Superconductivity 0103 physical sciences Quantum Physics (quant-ph) 010306 general physics Quantum |
| Popis: | We study the behaviour of the Uhlmann connection in systems of fermions undergoing phase transitions. In particular, we analyse some of the paradigmatic cases of topological insulators and superconductors in dimension one, as well as the BCS theory of superconductivity in three dimensions. We show that the Uhlmann connection signals phase transitions in which the eigenbasis of the state of the system changes. Moreover, using the established fidelity approach and the study of the edge states, we show the absence of thermally driven phase transitions in the case of topological insulators and superconductors. We clarify what is the relevant parameter space associated with the Uhlmann connection so that it signals the existence of order in mixed states. 14 pages (including Supplemental Material); Updated with new results; Accepted for publication in Physical Review Letters |
| Databáze: | OpenAIRE |
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