2013/02/28 by Adam Rycerz
Materials Science · Physics and Astronomy · #Graphene research and applications #Quantum optics and atomic interactions #Theoretical and Computational Physics #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.87.195431
published as Phys. Rev. B 87, 195431 (2013) · Minor revisions, typos corrected, references and acknowledgments added. RevTeX, 10 pages, 10 figures
arxiv created 2013/04/29 · openalex publication_date 2013/05/17 · arxiv updated 2013/05/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate the effect of strain-induced gauge fields on statistical distribution of energy levels of triangular graphene nanoflakes with zigzag edges. In the absence of strain fields but in the presence of weak potential disorder such systems were found by Rycerz [Phys. Rev. B 85, 245424 (2012)] to display the spectral statistics of the Gaussian unitary ensemble (GUE) due to the effective time-reversal (symplectic) symmetry breaking. Here we show that in the absence of disorder, strain fields may solely lead to spectral fluctuations of GUE providing a nanoflake is deformed such that all its geometric symmetries are broken. In a particular case when a single mirror symmetry is preserved the spectral statistics follow the Gaussian orthogonal ensemble (GOE) rather then GUE. The corresponding transitions to quantum chaos are rationalized by means of additive random-matrix models and the analogy between strain-induced gauge fields and real magnetic fields is discussed.