Finite temperature physics of 1D topological Kondo insulator: Stable Haldane phase, emergent energy scale and beyond
In recent years, interacting topological insulators have emerged as new frontiers in condensed matter physics, and the hotly studied topological Kondo insulator (TKI) is one of such prototypes. Although its zero-temperature ground-state has been widely investigated, the finite temperature physics on TKI is largely unknown. Here, we explore the finite temperature properties in a simplified model for TKI, namely the one-dimensional p-wave periodic Anderson model, with numerically exact determinant quantum Monte Carlo simulation. It is found that the topological Haldane phase established for groundstate is still stable against small thermal fluctuation and its characteristic edge magnetization develops at low temperature. Such facts emphasize the robustness of (symmetry-protected) topological order against temperature effect, which always exists at real physical world. Moreover, we use the saturated low-T spin structure factor and the 1/T - law of susceptibility to detect the free edge spin moment, interestingly the low-temperature upturn behavior of the latter one is similar to experimental finding in SmB6 at T < 50 K. It implies that similar physical mechanism may work both for idealized models and realistic correlated electron materials. We have also identified an emergent energy scale Tcr, which signals a crossover into interesting low-T regime and seems to be the expected Ruderman–Kittel–Kasuya–Yosida coupling. Finally, the collective Kondo screening effect has been examined and it is heavily reduced at boundary, which may give a fruitful playground for novel physics beyond the wellestablished Haldane phase and topological band insulators.
Keywordstopological Kondo insulator heavy fermion quantum Monte Carlo Haldane phase
This research was supported in part by the National Natural Science Foundation of China under Grant Nos. 11325417, 11674139, and 11704166, the Fundamental Research Funds for the Central Universities, Science Challenge Project under Grant No. JCKY2016212A502, SPC-Lab Research Fund (NO. XKFZ201605) and the Foundation of LCP.
- 8.C. X. Liu, S. C. Zhang, and X. L. Qi, The quantum anomalous Hall effect: Theory and experiment, Annu. Rev. Condens. Matter Phys. 7(1), 301 (2016)Google Scholar
- 11.J. Jiang, S. Li, T. Zhang, Z. Sun, F. Chen, Z. R. Ye, M. Xu, Q. Q. Ge, S. Y. Tan, X. H. Niu, M. Xia, B. P. Xie, Y. F. Li, X. H. Chen, H. H. Wen, and D. L. Feng, Observation of possible topological in-gap surface states in the Kondo insulator SmB6 by photoemission, Nat. Commun. 4(1), 3010 (2013)ADSCrossRefGoogle Scholar
- 12.M. Neupane, N. Alidoust, S. Y. Xu, T. Kondo, Y. Ishida, D. J. Kim, C. Liu, I. Belopolski, Y. J. Jo, T. R. Chang, H. T. Jeng, T. Durakiewicz, L. Balicas, H. Lin, A. Bansil, S. Shin, Z. Fisk, and M. Z. Hasan, Surface electronic structure of the topological Kondo-insulator candidate correlated electron system SmB6, Nat. Commun. 4(1), 2991 (2013)ADSCrossRefGoogle Scholar
- 14.B. S. Tan, Y. T. Hsu, B. Zeng, M. C. Hatnean, N. Harrison, Z. Zhu, M. Hartstein, M. Kiourlappou, A. Srivastava, M. D. Johannes, T. P. Murphy, J. H. Park, L. Balicas, G. G. Lonzarich, G. Balakrishnan, and S. E. Sebastian, Unconventional Fermi surface in an insulating state, Science 349(6245), 287 (2015)ADSCrossRefGoogle Scholar
- 15.G. Baskaran, Majorana Fermi sea in insulating SmB6: A proposal and a theory of quantum oscillations in Kondo insulators, arXiv: 1507.03477Google Scholar
- 27.R. R. dos Santo, Introduction to quantum Monte Carlo simulations for fermionic systems, Braz. J. Phys. 33, 1 (2003)Google Scholar
- 35.A. M. Lobos, A. O. Dobry, and V. Galitski, Magnetic end states in a strongly interacting one-dimensional topological Kondo Insulator, Phys. Rev. X 5(2), 021017 (2015)Google Scholar
- 40.K. Kummer, S. Patil, A. Chikina, M. Güttler, M. Höppner, et al., Temperature-independent Fermi surface in the Kondo lattice YbRh2Si2, Phys. Rev. X 5(1), 011028 (2015)Google Scholar