Starts 22 Apr 2026 11:00
Ends 22 Apr 2026 11:30
Central European Time
CMSP Seminar (Atomistic Simulation Seminar Series): Tuning Band Topology with Pressure: A First-Principles Study
Euler Lecture Hall (Leonardo Building) and via Zoom
Anita Francis
(ICTP)
(ICTP)
Abstract:
Topological insulators are a novel class of materials that are characterized by insulating bulk states and robust, symmetry protected metallic surface states [1, 2, 3]. In this seminar, I will first introduce the key concepts underlying the topological phases of matter, ways to characterize them, and the role of symmetry in their protection. I will then discuss how external parameters like pressure can be used as a clean knob to tune the topological nature of bands and drive topological phase transitions. As a case study I will discuss the recent results on TaSe3, a quasi-1D material, where applied pressure induces multiple topological quantum phase transitions [4]. These results highlight the interplay between lattice structure and band topology, and demonstrate how pressure can be used to engineer and control topological properties in real materials.
References:
[1] J. E. Moore, “The birth of topological insulators,” Nature, vol. 464, pp. 194–198, Mar 2010.
[2] J. E. Moore and L. Balents, “Topological invariants of time-reversal-invariant band structures,” Phys. Rev. B, vol. 75, p. 121306, Mar 2007.
[3] L. Fu, C. L. Kane, and E. J. Mele, “Topological insulators in three dimensions,” Phys. Rev. Lett., vol. 98, p. 106803, Mar 2007.
[4] A. G. Francis, J. Sunil, A. Joseph, A. Das, B. Joseph, K. A. Irshad, K. Biswas, S. K. Pati, and C. Narayana, “Evolution of topological phases of tase3 under hydrostatic pressure,” Phys. Rev. B, vol. 112, p. 085115, Aug 2025.
Topological insulators are a novel class of materials that are characterized by insulating bulk states and robust, symmetry protected metallic surface states [1, 2, 3]. In this seminar, I will first introduce the key concepts underlying the topological phases of matter, ways to characterize them, and the role of symmetry in their protection. I will then discuss how external parameters like pressure can be used as a clean knob to tune the topological nature of bands and drive topological phase transitions. As a case study I will discuss the recent results on TaSe3, a quasi-1D material, where applied pressure induces multiple topological quantum phase transitions [4]. These results highlight the interplay between lattice structure and band topology, and demonstrate how pressure can be used to engineer and control topological properties in real materials.
References:
[1] J. E. Moore, “The birth of topological insulators,” Nature, vol. 464, pp. 194–198, Mar 2010.
[2] J. E. Moore and L. Balents, “Topological invariants of time-reversal-invariant band structures,” Phys. Rev. B, vol. 75, p. 121306, Mar 2007.
[3] L. Fu, C. L. Kane, and E. J. Mele, “Topological insulators in three dimensions,” Phys. Rev. Lett., vol. 98, p. 106803, Mar 2007.
[4] A. G. Francis, J. Sunil, A. Joseph, A. Das, B. Joseph, K. A. Irshad, K. Biswas, S. K. Pati, and C. Narayana, “Evolution of topological phases of tase3 under hydrostatic pressure,” Phys. Rev. B, vol. 112, p. 085115, Aug 2025.