Overcoming Boltzmann's Tyranny in a Transistor via the Topological Quantum Field Effect

Muhammad Nadeem, Iolanda Di Bernardo, Xiaolin Wang, Michael S. Fuhrer, Dimitrie Culcer

Research output: Contribution to journalArticleResearchpeer-review

33 Citations (Scopus)


The subthreshold swing is the critical parameter determining the operation of a transistor in low-power applications such as switches. It determines the fraction of dissipation due to the gate capacitance used for turning the device on and off, and in a conventional transistor it is limited by Boltzmann's tyranny to kBT ln(10)/q. Here, we demonstrate that the subthreshold swing of a topological transistor in which conduction is enabled by a topological phase transition via electric field switching, can be sizably reduced in a noninteracting system by modulating the Rashba spin-orbit interaction. By developing a theoretical framework for quantum spin Hall materials with honeycomb lattices, we show that the Rashba interaction can reduce the subthreshold swing by more than 25% compared to Boltzmann's limit in currently available materials but without any fundamental lower bound, a discovery that can guide future material design and steer the engineering of topological quantum devices.

Original languageEnglish
Pages (from-to)3155-3161
Number of pages7
JournalNano Letters
Issue number7
Publication statusPublished - 14 Apr 2021


  • 2D Topological Insulators
  • Boltzmann’s tyranny
  • Rashba spin−orbit interaction
  • Spin−orbit coupled Xene nanoribbons
  • Subthreshold swing
  • Topological Transistors

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