RT Journal Article
T1 Two-dimensional density-matrix topological fermionic phases: topological Uhlmann numbers
A1 Viyuela García, Óscar
A1 Rivas Vargas, Ángel
A1 Martín-Delgado Alcántara, Miguel Ángel
AB We construct a topological invariant that classifies density matrices of symmetry-protected topological orders in two-dimensional fermionic systems. As it is constructed out of the previously introduced Uhlmann phase, we refer to it as the topological Uhlmann number n_(U). With it, we study thermal topological phases in several two-dimensional models of topological insulators and superconductors, computing phase diagrams where the temperature T is on an equal footing with the coupling constants in the Hamiltonian. Moreover, we find novel thermal-topological transitions between two nontrivial phases in a model with high Chern numbers. At small temperatures we recover the standard topological phases as the Uhlmann number approaches to the Chern number.
PB American Physical Society
SN 0031-9007
YR 2014
FD 2014-08-13
LK https://hdl.handle.net/20.500.14352/35592
UL https://hdl.handle.net/20.500.14352/35592
LA eng
NO © 2014 American Physical Society. We are thankful for the following: the Spanish MINECO Grants No. FIS2012-33152 and No. FIS2009-10061, the CAM research consortium QUITEMAD S2009-ESP-1594, the European Commission PICC: FP7 2007-2013, Grant No. 249958, the UCM-BS Grant No. GICC-910758, and the FPU MEC Grant and Residencia de Estudiantes.
NO Unión Europea. FP7
NO Ministerio de Economía y Competitividad (MINECO)
NO Comunidad de Madrid
NO Universidad Complutense de Madrid/Banco de Santander
NO FPU MEC
DS Docta Complutense
RD 20 abr 2025