scholarly journals Z2 topological invariants for mixed states of fermions in time-reversal invariant band structures

2021 ◽  
Vol 104 (21) ◽  
Author(s):  
Lukas Wawer ◽  
Michael Fleischhauer
Keyword(s):  
Time Reversal ◽  
Topological Invariants ◽  
Mixed States ◽  
Band Structures

scholarly journals Anomalies and renormalization of mixed states in quantum theories

2014 ◽  
Vol 29 (13) ◽  
pp. 1450064 ◽  
Author(s):  
Kumar S. Gupta ◽  
Amilcar de Queiroz
Keyword(s):  
Moduli Space ◽  
Time Reversal ◽  
Condensed Matter ◽  
Quantum Spin ◽  
Hamiltonian Approach ◽  
Mixed States ◽  
Expectation Values ◽  
Quantum Theories ◽  
Long Wavelength ◽  
Mass Gap

In a Hamiltonian approach to anomalies, parity and time-reversal symmetries can be restored by introducing suitable impure (or mixed) states. However, the expectation values of observables such as the Hamiltonian diverges in such impure states. Here, we show that such divergent expectation values can be treated within a renormalization group (RG) framework, leading to a set of β-functions in the moduli space of the operators representing the observables. This leads to well-defined expectation values of the Hamiltonian in a phase where the impure state restores the P and T symmetry. We also show that this RG procedure leads to a mass gap in the spectrum. Such a framework may be relevant for long wavelength descriptions of condensed matter systems such as the quantum spin Hall (QSH) effect.

scholarly journals Topological Invariants in Fermi Systems with Time-Reversal Invariance

1988 ◽  
Vol 61 (12) ◽  
pp. 1329-1332 ◽  
Author(s):  
J. E. Avron ◽  
L. Sadun ◽  
J. Segert ◽  
B. Simon
Keyword(s):  
Time Reversal ◽  
Topological Invariants ◽  
Time Reversal Invariance ◽  
Fermi Systems ◽  
Reversal Invariance

Band structures of NaCl structure uranium compounds

1979 ◽  
Vol 40 (C4) ◽  
pp. C4-19-C4-21 ◽  
Author(s):  
R. Allen ◽  
M. S.S. Brooks
Keyword(s):  
Band Structures ◽  
Uranium Compounds

Time Reversal in Lossy Material: An Assessment

PIERS Online ◽  
2006 ◽  
Vol 3 (8) ◽  
pp. 1259-1263
Author(s):  
Ian Scott ◽  
Ana Vukovic ◽  
Phillip Sewell
Keyword(s):  
Time Reversal ◽  
Lossy Material
Sign in / Sign up

Export Citation Format

Share Document