Interacting bosons on a Su-Schrieffer-Heeger ladder: Topological phases and Thouless pumping

Ashirbad Padhan, Suman Mondal, Smitha Vishveshwara, Tapan Mishra

Research output: Contribution to journalArticlepeer-review


We study the topological properties of hardcore bosons on a two-leg ladder consisting of two Su-Schrieffer-Heeger chains that are coupled via hopping and interaction. We chart out the phase diagram for the system and show that based on the relative hopping dimerization pattern along the legs, distinctly different topological phases and phase transitions can occur. When the dimerization along the legs is uniform, we find that the topological nature vanishes for even the slightest rung hopping. For staggered dimerization, the system exhibits a well-defined topological character and a topological phase transition as a function of rung hopping. While the topological phase shows bond order character, the trivial phase shows the behavior of a rung-Mott insulator. For this case, the topological nature is found to survive even in the presence of finite interleg interactions. Moreover, we find that the critical point of the topological phase transition shifts to a higher or a lower rung hopping strength depending on the attractive or repulsive nature of the interaction. To highlight the marked effects of interactions, we propose a scheme involving a Thouless charge pump that provides insights for the topological phases characterized by a quantized particle transport through a periodic modulation of appropriate system parameters. In our studies, we show an interaction-induced charge pumping following specific pumping protocols in the case of staggered dimerization.

Original languageEnglish (US)
Article number085120
JournalPhysical Review B
Issue number8
StatePublished - Feb 15 2024

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics


Dive into the research topics of 'Interacting bosons on a Su-Schrieffer-Heeger ladder: Topological phases and Thouless pumping'. Together they form a unique fingerprint.

Cite this